Engineering Commons^™

Xps And Ipe Determination Of Band Offsets Of Germanium Based Materials, Justin Michael Rudie

Graduate Theses and Dissertations

Germanium tin and silicon germanium tin are group IV semiconductor alloys that have gained significant interest in recent years for their potential use in optoelectrical devices. While silicon and germanium are indirect bandgap materials on their own, alloying them with tin in sufficient quantities leads to a transition to direct bandgap alloys. Direct gap performance opens the door for efficient light emitting and detecting devices fabricated entirely on group IV materials that are compatible with the industry standard CMOS manufacturing techniques. Germanium tin and silicon germanium tin have bandgaps that respond to light in the mid to near infrared spectrum …

Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of thermoelectric and lattice dynamics properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Se, Te) and ZrS2 compounds based on the first-principles density functional theory. The dimensionality reduction (e.g., using 2D structure) of bulk materials is found to have enhanced thermoelectric efficiency. This enhancement is attributed to the increase of the Seebeck coefficient as a result of higher electronic density of states near the Fermi level in low-dimensional materials. In addition, lowering the dimensionality increases phonon scattering near interfaces and surfaces in 2D materials, which leads to a …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

Etching Process Development For Sic Cmos, Weston Reed Renfrow

Graduate Theses and Dissertations

Silicon Carbide (SiC) is an exciting material that is growing in popularity for having qualities that make it a helpful semiconductor in extreme environments where silicon devices fail. The development of a SiC CMOS is in its infancy. There are many improvements that need to be made to develop this technology further. Photolithography is the most significant bottleneck in the etching process; it was studied and improved upon. Etching SiC can be a challenge with its reinforced crystal structure. Chlorine-based inductively coupled plasma (ICP) etching of intrinsic SiC and doped SiC, SiO2, and Silicon has been studied. A baseline chlorine …

Evaluation Of Single Phase Smart Pv Inverter Functions In Unbalanced Residential Distribution Systems, Darren Symonette

Graduate Theses and Dissertations

In the United States, smart PV inverters integrated with residential distribution systems are becoming a more common occurrence. With integration of smart PV inverters, power utilities are experiencing an increase of number of operations with regards to switched capacitor banks, voltage regulators and on load tap changers. These increases can lead to excess wear and tear on the devices causing power utilities to perform unwanted replacement and maintenance. However, smart PV inverters when controlled under specific functions can enable these inverters to provide reactive power and voltage control which in turn lowers the number of operations for switched capacitor banks, …

Full Disclosure: Model Uncertainty In Adjusting For Confounders, Dieudonne Dusenge

Graduate Theses and Dissertations

This study examines the role of knowledge about underlying causal relationships in classifying controls in order to mitigate omitted- and included-variable biases. Using simulations and accounting examples, the study shows that the researcher may not distinguish good and bad controls because the underlying causal relationships are unobservable, and remedying strategies (such as the relative timing of measurement) may not remove the uncertainty in the classification. Because of the uncertainty about which controls to use, two or more models will be credible as will the distinct estimates derived from them. Next, the study shows that the current standard practice of singling …

Study Of Single-Photon Wave-Packets With Atomically Thin Nonlinear Mirrors, Christopher Klenke

Graduate Theses and Dissertations

A novel controlled phase gate for photonic quantum computing is proposed by exploiting the powerful nonlinear optical responses of atomically thin transition metal dichalcogenides (TMDs) and it is shown that such a gate could elicit a π-rad phase shift in the outgoing electric field only in the case of two incident photons and no other cases. Firstly, the motivation for such a gate is developed and then the implementation of monolayer TMDs is presented as a solution to previous realization challenges. The single-mode case of incident photons upon a TMD is derived and is then used to constrain the more …

Implementation Of Secondary And Tertiary Treated Wastewater In Concrete Manufacturing, Amany G. Micheal Prof., Haidy Abdel Salam, Gouda Ghanem

Civil Engineering

Water scarcity is a problem that faces many regions. In a developing and arid country like Egypt, the need for freshwater is exponentially increasing. This research is an evaluation of the recycled wastewater to be used in concrete manufacturing. The treated wastewater is blended with potable water with percentages of 25%, 50%, and 100%. The mixture of the two types of water is used in concrete mixing and curing. Control specimens with pure potable water are cast for comparison. The setting time for Ordinary Portland Cement is tested using the different water mixes. The hardened concrete is tested in compression …

A Lacunarity-Based Index For Spatial Heterogeneity, Ryan H. Scott, Hawwa Falih Kadum, G. Salmaso, Marc Calaf, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Characteri zing spatial heterogeneity is fundamental in numerous areas, yet defining spatial patterns often depends on qualitative assessments or a priori knowledge. Lacunarity analysis is a popular occupancy-based method for identi fy ing relevant length scales in spatially heterogeneous systems. From lacunarity, we identify the ex istence of a point which encapsulates the spatial heterogeneity of a given system. This value sati sfies the conditions for the lac unarity cutoff function and forms the bas is of a heterogeneity index. We evaluate the behavior of both parameters in mono fractal, clustered, and periodic systems. ln addition, we demonstrate the broad …

Securing Information On A Web Application System To Facilitate Online Blood Donation Booking, Hrishitva Patel

Faculty Publications

Blood donation has saved many lives in the past. According to statistics presented by the American Red Cross, a patient is in need of a blood transfusion every two seconds. There are many benefits that arise from blood donation to both the donor and the blood recipients. With blood donation, cancer patients, people involved in accidents, or those battling diseases that require blood donation have access to enough blood to sustain their survival. There is a need to digitize the blood donation booking to facilitate blood donation across the United States, and ensure patients in need of blood, receive their …

A Novel Testbed For Evaluation Of Operational Technology Communications Protocols And Their On-Device Implementations, Matthew Boeding

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Operational Technology (OT) and Infrastructure Technology (IT) systems are converging with the rapid addition of centralized remote management in OT systems. Previously air-gapped systems are now interconnected through the internet with application-specific protocols. This has led to systems that had limited access points being remotely accessible. In different OT sectors, legacy protocols previously transmitted over serial communication were updated to allow internet communication with legacy devices. New protocols such as IEC-61850 were also introduced for monitoring of different OT resources. The IEC-61850 standard’s Generic Object Oriented Substation Event (GOOSE) protocol outlines the representation and communication of a variety of different …

Predicting The Impact Of Utility Lighting Rebate Programs On Promoting Industrial Energy Efficiency: A Machine Learning Approach, Phillip Shook, Jun-Ki Choi

Mechanical and Aerospace Engineering Faculty Publications

Implementation costs are a major factor in manufacturers' decisions to invest in energy-efficient technologies. Emerging technologies in lighting systems, however, typically require small investment costs and offer short, simple payback periods, due, in part, to federal, state, and utility incentive programs. Recently, however, certain state and federal mandates have reduced the support for and efficacy of electricity utility incentivizing programs. To determine the impact of such support programs, this study examined historical data regarding lighting retrofit savings, implementation costs, and utility rebates gathered from 13 years of industrial energy audits by a U.S. Department of Energy Industrial Assessment Center in …

Teaching Learning Newsletter Vol 2 Issue 2, Sastra Deemed To Be University

TLC Newsletter

No abstract provided.

Replacing Combustion Engines With Hydrogen Fuel Cells To Power Mining Haul Trucks: Challenges And Opportunities, Ayorinde Akinrinlola

Masters Theses

"With the proven advantage of higher energy density in hydrogen fuel cells over batteries, there is potential to apply fuel cells to power mining haul trucks. This study aims to evaluate the technical and economic feasibility of hydrogen fuel cell electric mine trucks as an alternative to current mine haul trucks. Specifically, the project: (1) developed an economic framework for evaluating the integration of renewable energy powered haul trucks into mining; and (2) applied vehicle drivetrain and energy simulation in Matlab/Simulink to elucidate the challenges and opportunities of incorporating hydrogen fuel cell technology into the current form factors of mine …

Modeling The Reactor Time-Dependent Delayed Particle Tail With Monte Carlo N-Particle (Mcnp) Version 6.2, Eli James Boland

Masters Theses

"Energy is deposited into experiment packages due to post-shutdown decay heat created from delayed particles. Modeling these delayed particles in a reactor assists researchers in quantifying the expected energy deposition sources to an experiment package before irradiation. This paper focuses on modeling the delayed particles in a reactor in MCNP6.2 by capturing a reactor as a source, converting this source capture to a source definition, applying appropriate physics such as activation and photonuclear interactions, and finally using proper tallies to create the expected delayed particle tail of a reactor.

To capture the source distribution, the FMESH capability within MCNP was …

Personalizing Student Graduation Paths Using Expressed Student Interests, Nicolas Charles Dobbins

Masters Theses

"This work proposes an intelligent recommender approach to facilitate personalized education and help students in planning their path to graduation. The original research contribution of this work is to develop a recommender approach that pervasively personalizes and optimizes a student’s path to graduation by accounting for the student’s career interests and academic background. The approach is a multi-objective optimization problem, subject to institutional constraints, with the goal of optimizing the graduation path with respect to one or more criteria, such as time-to-graduation, credit hours taken, and alignment with student’s career interests. The efficacy of the approach is illustrated and verified …

Understanding Charge Effects On Marked Ball Wear Rates – A Corrosion Study, John Bailey Fletcher

Masters Theses

"To measure the wear rates of grinding balls within a ball mill, marked ball wear tests (MBWTs) have been used extensively. Using the wear rates from a MBWT, operators select the most cost-effective media for their grinding application. One factor that a MBWT does not account for is the possible interaction between different media materials which could affect their corrosion rates. Galvanic coupling between dissimilar metals can cause significant changes in their corrosion rates. While galvanic interactions between minerals and grinding media have been studied, the interaction between dissimilar media has not. Corrosion rates and potentials of modern high carbon …

Effect Of Boron In Cast Iron, Suyash Durendra Pawaskar

Masters Theses

"Boron, mostly considered a residual element, has started to cause issues in the cast iron foundries by causing a decrease in the strength of pearlitic gray and ductile iron castings. Because of the increase in the use of boron-added steel scrap from automotive steel and a lack of agreement on the critical levels of boron in cast iron, foundries are facing difficulties in controlling the microstructure of gray iron castings when boron is present. The current investigation was designed to analyze the effects of boron in cast irons and predict a mechanism to understand its effects with a vision of …

Advanced Topologies Of High Step-Up Dc-Dc Converters For Renewable Energy Applications, Ramin Rahimi

Doctoral Dissertations

"This research is focused on developing several advanced topologies of high step-up DC-DC converters to connect low-voltage renewable energy (RE) sources, such as photovoltaic (PV) panels and fuel cells (FCs), into a high-voltage DC bus in renewable energy applications. The proposed converters are based on the combinations of various voltage-boosting (VB) techniques, including interleaved and quadratic structures, switched-capacitor (SC)-based voltage multiplier (VM) cells, and magnetically coupled inductor (CI) and built-in-transformer (BIT). The proposed converters offer outstanding features, including high voltage gain with low or medium duty cycle, a small number of components, low current and voltage stresses on the components, …

Deep Learning Applications In Industrial And Systems Engineering, Winthrop Harvey

Graduate Theses and Dissertations

Deep learning - the use of large neural networks to perform machine learning - has transformed the world. As the capabilities of deep models continue to grow, deep learning is becoming an increasingly valuable and practical tool for industrial engineering. With its wide applicability, deep learning can be turned to many industrial engineering tasks, including optimization, heuristic search, and functional approximation. In this dissertation, the major concepts and paradigms of deep learning are reviewed, and three industrial engineering projects applying these methods are described. The first applies a deep convolutional network to the task of absolute aerial geolocalization - the …

Utilizing Prefabrication In Order To Achieve Leed Credits, Phillip E. Waldman

Construction Management

This paper is a dissertation on the concept and benefits of utilizing panelization in construction to achieve LEED credits. Panelization is the process of prefabricating construction framing materials, such as walls, floors, and roof systems, to streamline and improve the construction process. This dissertation aims to examine: (1) how prefabrication can optimize construction through effective waste management (2) how prefabrication manufacturing plants are more efficient, cost-effective, and better for the environment with regard to material use and recycling than traditional construction methods (3) how prefabrication can be used to obtain LEED credit points for the Construction and Demolition Waste Management …

Ultrashort Pulse Laser Filamentation Electrical And Optical Diagnostic Comparison, James E. Wymer

Optical Science and Engineering ETDs

Results presented here examine the effect of changing gas pressure on the radio frequency (RF) emissions of an ultrashort pulse laser filament plasma and how those emissions vary longitudinally in the laser focal region. We use a WR284 rectangular waveguide with a 1.5 cm hole that allows the beam through. A 3.2 GHz microwave signal is emitted in the waveguide, and signals are received through a waveguide-to-coax antenna connected to an HP8470B Schottky diode. By enabling and disabling the 3.2 GHz signal, we measure both the self-emitted RF from a USPL filament and subsequently the degree of attenuation a filament …

Design, Microfabrication And Characterization Of Vibrating Mesh Atomizer For Viscous Fluids, Pallavi Sharma

Mechanical Engineering ETDs

This research focuses on a new piezoelectrically driven Micro Electromechanical Systems based vibrating mesh atomizer that generates the pressure differential required for droplet ejection or spray production using frequency resonances in the 100 kHz range. This study involves device construction and experimental characterization to comprehend the device's operation and the influence of various factors on its performance and determine the limitations of a range of working fluids to atomize.

A novel approach to integrating polymer-based micro heaters with a vibrating mesh atomizer as a monolithic component is presented to expand the range of working liquids for the MEMS device. The …

Production Of Polyhydroxybutyrate From Corn Fiber Using Paraburkholderia Sacchari, Twissa Mitra

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

Poly(3-hydroxybutyrate) (PHB) is one of the most broadly studied members of the polyhydroxyalkanoates (PHA) family. It is a fully biodegradable thermoplastic produced by microbial fermentation having properties similar to polypropylene. PHB has a market price that is three times higher than the cost of synthetic plastics. Substrate cost makes up 50 to 60 % of that cost; hence, researchers have been exploring various cheap natural resources with high carbohydrate content to be used as a substrate for PHB production.

In this study, corn fiber, a lignocellulosic biomass has been studied as an option for a substrate to produce PHB. This …

Compound Flooding In Convergent Estuaries: Insights From An Analytical Model, Ramin Familkhalili, Stefan Talke, David A. Jay

Civil & Environmental Engineering Faculty Publications

We investigate here the effects of geometric properties (channel depth and cross-sectional convergence length), storm surge characteristics, friction, and river flow on the spatial and temporal variability of compound flooding along an idealized, meso-tidal coastal-plain estuary. An analytical model is developed that includes exponentially convergent geometry, tidal forcing, constant river flow, and a representation of storm surge as a combination of two sinusoidal waves. Nonlinear bed friction is treated using Chebyshev polynomials and trigonometric functions, and a multi-segment approach is used to increase accuracy. Model results show that river discharge increases the damping of surge amplitudes in an estuary, while …

Augmented Reality For Human Control Of Engineering Tasks, Elijah Wyckoff

Mechanical Engineering ETDs

This research is motived by the study of dynamics, especially in experimentation and Structural Health Monitoring (SHM) methods. It is important that inspectors maintain awareness of test structures while observing sensor data and inputting control. Humans receive a large amount of information from vision, and this feedback is crucial to inform decision making. Human-computer interaction (HCI) provides valuable data and information but separates the human from reality as it is necessary to look away from the region of interest to view information on a separate device. Additionally, sensor data does not collect experiment safety, quality, and other contextual information of …

Gp-K: A Probabilistic Method For Hourly Day-Ahead Power Load Forecasting, Miguel A. Hombrados-Herrera

Electrical and Computer Engineering ETDs

The elevated costs that incur power grid stakeholders due to forecasting errors in power load demand have created the need for forecasting methods that provide accurate predictions and allow for assessing the reliability of their predictions. This thesis proposes a probabilistic forecasting method for multi-step ahead forecasting.

In particular, it presents a probabilistic method to perform a 24-hours-ahead power load forecasting that arises as the combination of Gaussian Process regressors with NMF (nonnegative matrix factorization) and integrates the advantages of both methods. Instead of training 24 independent processes for each hour of the predicted day, this work proposes to factorize …

Combinatorial Cnn Meta-Structures In Deep Learning Applications, Aswathy Rajendra Kurup

Electrical and Computer Engineering ETDs

The study aims in applying combinatorial structures motivated from the basic CNN in various applications. Convolutional neural networks (CNNs) have grown to be very popular in the field of deep learning. The ability of such networks to learn both Spatial and temporal characteristics in the data have helped in deploying them in various fields. Through this research we explore different kinds of CNN-derived architectures and how these structures can be trained and setup in combinatorial environment to solve problems in deep learning applications. First, we introduce the basic idea of a deep learning meta-structures which is used in the application …

Pesticide Application Management Toolset For Worker Protection Standards, Nathan W. Thorson

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

The application of Pesticides has become a widely adopted practice within modern agriculture, however this practice poses a significant health risk to farm workers and crop advisors when pesticide exposures occur. Current safety standards require documentation of each application to help mitigate human exposure, yet these standards rely heavily on antiquated data collection formats and complex communication systems putting little emphasis on notification timeliness. Our objective was to reduce the risk of pesticide exposure for all farm workers and crop advisors by utilizing technological automation processes to reduce the number of links within the communication system. This proved successful though …

Cybersecurity Of Agricultural Machinery: Exploring Cybersecurity Risks And Solutions For Secure Agricultural Machines, Mark Freyhof

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

Modern agriculture is reliant on agricultural machinery for the production of food, fuel, and other agricultural products. The need for producing large quantities of quality agricultural products while sustainably stewarding environmental resources has led to the integration of numerous digital technologies into modern agricultural machinery, such as the CAN bus and telematic control units (Liu et al., 2021). An unintended drawback of these integrated digital technologies is the opportunity for these components to become cyberattack vectors. Cyberattack instances have increasingly targeted critical infrastructures, with numerous reports from agencies such as the Federal Bureau of Investigation (FBI) and Department of Homeland …