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Full-Text Articles in Engineering

Sustainable Agricultural Development In The Western Desert Of Egypt Under Climate Change: A Case Study Of The Siwa Region, Noha Hossam Moghazy May 2021

Sustainable Agricultural Development In The Western Desert Of Egypt Under Climate Change: A Case Study Of The Siwa Region, Noha Hossam Moghazy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Siwa region located in the Western Desert of Egypt is a natural depression and has a large volume of groundwater from the non-renewable Nubian Sandstone Aquifer System (NSAS). Recently the government initiated a development project to reclaim 1.5 million acres where most of the lands are located in the Western Desert to use available groundwater from NSAS. The primary goal of this project is to increase agricultural areas enabling rural development. Siwa is one of the areas that will be reclaimed in the desert by about 30,000 acres consisting of good soil quality. This dissertation aims to understand the …


Three-Phase Unfolding Based Soft Dc-Link Converter Topologies For Ac To Dc Applications, Dorai Babu Yelaverthi May 2021

Three-Phase Unfolding Based Soft Dc-Link Converter Topologies For Ac To Dc Applications, Dorai Babu Yelaverthi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Battery electric vehicles (BEVs) and plugin hybrid electric vehicles (PHEVs) are more efficient than internal combustion-based vehicles. Adaption of EVs will help reduce the carbon emissions produced by the transportation sector. The charging infrastructure has to grow at a rapid pace to encourage EV adaption. Installing higher capacity fast chargers will help alleviate the range anxiety of battery electric vehicle customers. More public charging stations are required for the full adaption of EVs. Utility power is distributed as ‘alternating current.’ A battery requires ‘direct current’ (DC) source to charge it. Hence a power converter that converts AC source to DC …


Sonic Boom Loudness Reduction Through Localized Supersonic Aircraft Equivalent-Area Changes, Troy A. Abraham May 2021

Sonic Boom Loudness Reduction Through Localized Supersonic Aircraft Equivalent-Area Changes, Troy A. Abraham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The NASA University Leadership Initiative (ULI) titled “Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation” looks to study the feasibility of distributed structural adaptivity on a supersonic aircraft for maintaining acceptable en-route sonic boom loudness during overland flight. The ULI includes a team of industry and university partners that are working together to develop and implement the systems necessary to accomplish this goal.

The Utah State University Aerolab is a member of this ULI team and has been tasked with developing and using low-fidelity supersonic aerodynamic and sonic boom predictions tools to rapidly study the effects of localized geometry changes on …


Biomethanation And Alkaline Wet Air Oxidation Of Water Hyacinth (Pontederia Crassipes) From Ozama River, Dominican Republic, Yessica A. Castro May 2021

Biomethanation And Alkaline Wet Air Oxidation Of Water Hyacinth (Pontederia Crassipes) From Ozama River, Dominican Republic, Yessica A. Castro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Obtaining valuable products from environmental remediation waste is a sustainable approach that contributes to the ecological well-being of developing countries. In the present work, the feasibility of the water hyacinth anaerobic digestion as a post-weed management practice in the Ozama River (Dominican Republic) was demonstrated. The estimated energy required for harvesting was lower than that produced during digestion. The biomethanation of water hyacinth was improved by Alkaline Wet Air Oxidation (AWAO), a thermochemical pretreatment process that almost doubled the methane production rate and increased the yield by 24% when conducted at high temperatures. At lower temperatures, the methane yield of …


Algorithms For The Calibration And Correction Of Texel Images Using Inertial Measurement Updates, Trevor C. Welch May 2021

Algorithms For The Calibration And Correction Of Texel Images Using Inertial Measurement Updates, Trevor C. Welch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A 3D terrain map can be developed to survey the earth’s surface and provide scientists with a method of accurately modeling terrain. Some of the applications include agricultural surveys, disaster management, and object classification. In order to develop a 3D terrain map, a sensor must capture all of the data to create the map. This 3D mapping tool can be made by combining a sensor that take samples of points on the earth’s surface and combines that with a digital camera that takes an image and lays it across those samples of the earth.

In order to take data over …


Design Of Miniaturized Sweeping Langmuir Probe And Electric Field Probe For The Sport Mission, Nathan P. Tipton May 2021

Design Of Miniaturized Sweeping Langmuir Probe And Electric Field Probe For The Sport Mission, Nathan P. Tipton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Scintillation Prediction Observation Research Task (SPORT) is a joint United States of America and Brazil 6U CubeSat mission. The US is providing the science instruments and the spacecraft launch. Brazil is providing the spacecraft bus, integration, and operations. Utah State University will provide four instruments for the mission as part of the US contribution in a suite called the Space Weather Probes (SWP). These instruments are the Sweeping Langmuir Probe (SLP), the Electric Field Probe (EFP), and the Sweeping Impedance Probe (SIP). Higher frequency components of the SLP and EFP will be observed through a Wave Spectrometer (WS). These …


Development Of A Variable Extensometer Method For Measuring Ductility Scaling Parameters, Adam J. Smith May 2021

Development Of A Variable Extensometer Method For Measuring Ductility Scaling Parameters, Adam J. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ductility is the measure of how much a material can stretch before separation. It is usually measured in percent elongation, which is the amount a material stretches divided by its original length before stretching. This is an important property to understand for both the design for performance and safety. A material’s ductility can be influenced by several factors including heat treatment, machining, temperature, and radiation dose. Materials used in nuclear energy facilities are often exposed to all these factors, and it is important to be able to understand ductility at each possible combination.

Ductility is usually characterized through tension tests …


Sensitivity And Estimation Of Aerodynamic, Propulsion, And Inertial Parameters For Rudderless Aircraft Using Simulation, Jaden W. Thurgood May 2021

Sensitivity And Estimation Of Aerodynamic, Propulsion, And Inertial Parameters For Rudderless Aircraft Using Simulation, Jaden W. Thurgood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique known as system identification is often used in aircraft design and testing to understand and validate the mathematical parameters that describe the aircrafts stability and handling characteristics. System identification can be thought of as the inverse of simulation. In the world of system identification, we have a physical system that we seek to understand in more detail by monitoring the system with an array of sensors. In short, we conduct tests of an aircraft while recording the inputs and response outputs. Then we take the input and output data and run it through an algorithm that seeks to …


Effects Of Climate Forcing Uncertainty On High-Resolution Snow Modeling And Streamflow Prediction In A Mountainous Karst Watershed, Conor Tyson May 2021

Effects Of Climate Forcing Uncertainty On High-Resolution Snow Modeling And Streamflow Prediction In A Mountainous Karst Watershed, Conor Tyson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Snow-dominated, karst watersheds present particular challenges to accurately modeling streamflow in response to differing climate conditions. This is due to the uneven distribution of snow within a basin, the varied melting rates due to terrain and climate, and the difficulty determining flow paths through karst conduits below ground. One possible solution to these challenges is to model snow at a fine scale, but climate variables are not available at these smaller spatial scales. The choices about which climate dataset to use, and how to downscale the data to a fine scale, will likely affect the accuracy of streamflow simulations. This …


Accounting For Critical Attributes And Uncertainty In Flow-Ecology Relationships, Elizabeth Decker Morgan May 2021

Accounting For Critical Attributes And Uncertainty In Flow-Ecology Relationships, Elizabeth Decker Morgan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Environmental flows are used to maintain streamflow for aquatic species in rivers while also sustaining human water requirements. While there are many approaches to develop environmental flows, they all rely on a strong conceptual understanding of flow-ecology relationships, which are often uncertain. Uncertainty in flow-ecology relationships can stem from using limited data to develop or test relationships or an incomplete understanding of the attributes inherent to each relationship, such as climate and land conditions. Accounting for these attributes and uncertainty in flow-ecology relationships is critical given mounting interest to develop and implement environmental flows at large scales, often with limited …


Application Of Flow And Ion Data To Estimate Ungaged Inflows And Losses In Urban And Agricultural Sub-Reaches Of The Logan River Observatory, Hyrum Tennant May 2021

Application Of Flow And Ion Data To Estimate Ungaged Inflows And Losses In Urban And Agricultural Sub-Reaches Of The Logan River Observatory, Hyrum Tennant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Streams in urban and agricultural environments are often heavily diverted for irrigation and drinking water purposes. These streams can receive inflow from unmeasured sources including stormwater returns, groundwater drains, and irrigation runoff that will help sustain flow during dry periods. Due to an inability to identify the source of most of these inflows or directly measure their volumes, there is a clear need for identification and quantification methods. Streamflow data from the Logan River Observatory illustrates the importance of unidentified inflows in sections influenced by large diversions. To understand the role of unidentified inflows and possible outflows in this portion …


Development Of A Two-Level Warping Algorithm And Its Application To Speech Signal Processing, Al-Waled H. Al-Dulaimi May 2021

Development Of A Two-Level Warping Algorithm And Its Application To Speech Signal Processing, Al-Waled H. Al-Dulaimi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In many different fields there are signals that need to be aligned or “warped” in order to measure the similarity between them. When two time signals are compared, or when a pattern is sought in a larger stream of data, it may be necessary to warp one of the signals in a nonlinear way by compressing or stretching it to fit the other. Simple point-to-point comparison may give inadequate results, because one part of the signal might be comparing different relative parts of the other signal/pattern. Such cases need some sort of alignment todo the comparison. Dynamic Time Warping ( …


Application Of Computational Fluid Dynamics To Determine Gas Expansion Factors Of Differential Pressure Flow Meters, Patrick L. Campana May 2021

Application Of Computational Fluid Dynamics To Determine Gas Expansion Factors Of Differential Pressure Flow Meters, Patrick L. Campana

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate if computer simulations could be used to accurately predict gas expansion in differential pressure flow meters. Differential pressure flow meters are used to measure the flow rate of pressurized liquids and gases through pipes. Computer simulations of liquid and gas flows were conducted for three distinct differential pressure flow meter geometries: Classical Venturis, Stand Concentric orifice plates, and wedge meters.

Gas flows were modeled as dry air using the assumption of a perfect gas. Expansion effects were modeled using the ideal gas law. Computer simulations of Classical Venturi and Standard Concentric orifice …


A Laboratory Study Of The Hydraulics Of Moderate-Sloped Stepped Chutes With A Labyrinth Crest, L. Kade Flake May 2021

A Laboratory Study Of The Hydraulics Of Moderate-Sloped Stepped Chutes With A Labyrinth Crest, L. Kade Flake

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Evolving methods of dam construction and rehabilitation require unique and innovative spillways. Spillways provide passage for water impounded by a dam. Stepped chute spillways offer an efficient and economical solution for dam construction and rehabilitation. Labyrinth weirs, which allow high flow discharge within a compact footprint, are often an economical solution for the spillway crest at a chute entrance. Labyrinth weirs have recently been combined with stepped chutes in several locations. However, published literature is scarce for the flow properties and key design parameters of these combined structures.

This study researched the hydraulics downstream of a labyrinth crest for two …


Computational Fluid Dynamics Benchmark Validation Experiment Of Plenum-To-Plenum Flow Through Vertical Heated Parallel Channels, Austin W. Parker May 2021

Computational Fluid Dynamics Benchmark Validation Experiment Of Plenum-To-Plenum Flow Through Vertical Heated Parallel Channels, Austin W. Parker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The next generation of nuclear power plants will have higher efficiency and improved safety, among other benefits; one attractive option is the high temperature gas reactor. An ability to predict the physics that occur within the reactor under normal conditions and accident scenarios is necessary before it receives regulatory licensing for use. The flow through a high temperature gas reactor involves complex interactions of heat transfer, fluids, and solids.

One method for simulating complex fluid dynamics is called Computational Fluid Dynamics. These simulations have already been used to predict the complex fluid flows found in high temperature gas reactors. Predicting …


Numerical Simulation Of Losses In Four-Way Pipe Junctions, Simon Barth May 2021

Numerical Simulation Of Losses In Four-Way Pipe Junctions, Simon Barth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To design pipelines, engineers need to know how much energy the fluid in the pipe has at different locations in the pipe network. The energy the fluid has comes in the form of pressure, velocity, and elevation. As fluid travels through a pipe, it loses energy for many different reasons. Some of those reasons include friction between the fluid and the pipe wall, shear forces within the fluid, changes in flow direction, changes in elevation, or various pipe fittings like elbows, tee’s, valves, reducers, and expanders. Many of the causes of energy loss are well researched. One cause of energy …


Demo Abstract: Porting And Execution Of Anomalies Detection Models On Embedded Systems In Iot, Bharath Sudharsan, Pankesh Patel, Abdul Wahid, Muhammad Yahya, John G. Breslin, Muhammad Intizar Ali May 2021

Demo Abstract: Porting And Execution Of Anomalies Detection Models On Embedded Systems In Iot, Bharath Sudharsan, Pankesh Patel, Abdul Wahid, Muhammad Yahya, John G. Breslin, Muhammad Intizar Ali

Publications

In the Industry 4.0 era, Microcontrollers (MCUs) based tiny embedded sensor systems have become the sensing paradigm to interact with the physical world. In 2020, 25.6 billion MCUs were shipped, and over 250 billion MCUs are already operating in the wild. Such low-power, low-cost MCUs are being used as the brain to control diverse applications and soon will become the global digital nervous system. In an Industrial IoT setup, such tiny MCU-based embedded systems are equipped with anomaly detection models and mounted on production plant machines for monitoring the machine’s health/condition. These models process the machine’s health data (from temperature, …


Automated Bottling Station - Packaging System, Lauren Nicole Zinzilieta May 2021

Automated Bottling Station - Packaging System, Lauren Nicole Zinzilieta

Honors College Theses

This report focuses on the packaging system used at the end of the FESTO bottling station that is located in EP 2355. The system will be made up of an x-y 300 mm x 300 mm gantry system, an Arduino, two micro-stepping stepper drivers, and two 152.4 mm (6 in) single acting cylinders with a 3D printed bracket attached to both. The gantry system will be located at the end of the conveyor belt and will be programmed to pick up three bottles at a time and then will move a specified number of steps in both the x and …


Analog Spiking Neural Network Implementing Spike Timing-Dependent Plasticity On 65 Nm Cmos, Luke Vincent May 2021

Analog Spiking Neural Network Implementing Spike Timing-Dependent Plasticity On 65 Nm Cmos, Luke Vincent

Graduate Theses and Dissertations

Machine learning is a rapidly accelerating tool and technology used for countless applications in the modern world. There are many digital algorithms to deploy a machine learning program, but the most advanced and well-known algorithm is the artificial neural network (ANN). While ANNs demonstrate impressive reinforcement learning behaviors, they require large power consumption to operate. Therefore, an analog spiking neural network (SNN) implementing spike timing-dependent plasticity is proposed, developed, and tested to demonstrate equivalent learning abilities with fractional power consumption compared to its digital adversary.


Environmental Geotechnics: Challenges And Opportunities In The Post-Covid-19 World, Arvin Farid May 2021

Environmental Geotechnics: Challenges And Opportunities In The Post-Covid-19 World, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for …


Advancing The Use Of Quality Control Tools For High-Density Data In Modern Manufacturing, Romina Dastoorian May 2021

Advancing The Use Of Quality Control Tools For High-Density Data In Modern Manufacturing, Romina Dastoorian

Dissertations

In modern manufacturing, advanced metrology systems are continually being incorporated into quality control (QC) systems to provide high-density (HD) datasets. These datasets can contain millions of measurements that can be used to represent a part’s whole geometry. While integrating HD datasets into QC systems has brought several opportunities to enhance the performance of QC systems, it has resulted in new challenges in this area as well. While significant amounts of research have been performed in this area, the QC research community still strives to tackle these challenges. This study identifies key challenges regarding incorporating HD datasets into QC systems. Specifically, …


Dynamics In Drops As Confined Systems Containing Nanoparticles: Reformation Of Nanoparticles And Evaporation Of Water, Vijitha Mohan, Xianjie Qiu, Partho Neogi May 2021

Dynamics In Drops As Confined Systems Containing Nanoparticles: Reformation Of Nanoparticles And Evaporation Of Water, Vijitha Mohan, Xianjie Qiu, Partho Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Brine is used to displace crude oil in a reservoir and its performance improves when brine contains nanoparticles. It is the presence of nanoparticles in confinements, such as at dynamic contact lines and in thin films, which is of importance. The investigators here have determined a fast way to obtain confined systems by evaporating a small drop of water containing nanoparticles. Water droplets containing nanoparticles of alumina or silica were evaporated on surfaces of polyethylene terephthalate sheets, which are partially wet by water, and glass which is fully wet. After the liquid in the drops evaporated, the residues were examined …


In Vivo Analysis Of A Proprietary Glass-Based Adhesive For Sternal Fixation And Stabilization Using Rabbit And Sheep Models, Cina Mehrvar, Emily Deignan, Mark Hurtig, Gideon Cohen, Paul Zalzal, Oleg Safir, Adel Alhalawani, Marcello Papini, Mark R. Towler May 2021

In Vivo Analysis Of A Proprietary Glass-Based Adhesive For Sternal Fixation And Stabilization Using Rabbit And Sheep Models, Cina Mehrvar, Emily Deignan, Mark Hurtig, Gideon Cohen, Paul Zalzal, Oleg Safir, Adel Alhalawani, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Wire cerclage remains the standard method of care for sternal fixation, following median sternotomy, despite being beset with complications. An emerging treatment option has been to augment the wires with an adhesive. A patented ionomeric glass (mole fraction: SiO2:0.48, ZnO:0.36, CaO:0.12, SrO:0.04) has been used to formulate GPC+, a glass polyalkenoate cement (GPC), by mixing it with poly(acrylic) acid (PAA) and de-ionized water. In a human cadaver study, this material, when applied with wire cerclage, was able to significantly reduce sternal instability. However, the material has yet to be tested in pertinent animal models. Here, after a series …


Computational Sentiment Analysis Of An Online Left Ventricular Assist Device Support Forum: Positivity Predominates, Melissa Austin, Abhiraj Saxena, Thomas O'Malley, Elizabeth Maynes, Henry Moncure, Nathan Ott, H. Todd Massey, Francesco Moscato, Antonio Loforte, John M Stulak, Vakhtang Tchantchaleishvili May 2021

Computational Sentiment Analysis Of An Online Left Ventricular Assist Device Support Forum: Positivity Predominates, Melissa Austin, Abhiraj Saxena, Thomas O'Malley, Elizabeth Maynes, Henry Moncure, Nathan Ott, H. Todd Massey, Francesco Moscato, Antonio Loforte, John M Stulak, Vakhtang Tchantchaleishvili

Division of Cardiology Faculty Papers

Background: The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach.

Methods: Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6).

Results: Sixty-six thousand eight hundred …


Understanding Process Controls On Flow Duration Curves Through A Novel Framework, Saba Ghotbi May 2021

Understanding Process Controls On Flow Duration Curves Through A Novel Framework, Saba Ghotbi

Electronic Theses and Dissertations, 2020-

Flow duration curve (FDC) is a hydrologically representation of the statistical distribution of daily streamflows. For a long time, hydrologists have sought deeper understanding of the process controls on the shape of FDC, which has been a challenge due to contrasting processes controlling the fast flow and slow flow components of streamflow and their interactions. This dissertation addresses the challenge by outlining a novel framework to explore the physical controls on FDC. The framework involves separating streamflow into fast flow and slow flow and studying their duration curves separately then combining them statistically to obtain FDC. Initially, the potential of …


Evaluation Of Visible Diffuse Reflectance Spectroscopy In Liver Tissue: Validation Of Tissue Saturations Using Extracorporeal Circulation, Stylianos Voulgarelis, Faraneh Fathi, Astrid G. Stucke, Kevin D. Daley, Joohyun Kim, Michael W. Zimmerman, Johhny C. Hong, Nicholas Starkey, Kenneth P. Allen, Bing Yu May 2021

Evaluation Of Visible Diffuse Reflectance Spectroscopy In Liver Tissue: Validation Of Tissue Saturations Using Extracorporeal Circulation, Stylianos Voulgarelis, Faraneh Fathi, Astrid G. Stucke, Kevin D. Daley, Joohyun Kim, Michael W. Zimmerman, Johhny C. Hong, Nicholas Starkey, Kenneth P. Allen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period.

Aim: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo.

Approach: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n=15) with validation via blood gas analysis.

Results: In vivo absorption and scattering measured by vis-DRS with and without biliverdin …


Simulation Of Transient Conditions In Vehicle-To-Grid Systems Fed From Plug-In Electric Vehicles, Olapade Oludolapo Olagbemi May 2021

Simulation Of Transient Conditions In Vehicle-To-Grid Systems Fed From Plug-In Electric Vehicles, Olapade Oludolapo Olagbemi

Masters Theses

The increasing adoption of plug-in electric vehicles for commercial and consumer needs, coupled with government targets and incentives for use of renewable energy sources and reduction of greenhouse gases [1, pp. 44-45], has led to their consideration as power sources. Such vehicle-to-grid (V2G) systems seek to take advantage of the aggregate energy available within fleets of electric vehicles connected to power grids through bi-directional charging stations, by using them as distributed power sources for load leveling and peak shaving on the power grids [2]. Unfortunately, V2G systems can introduce power quality issues, such as harmonics, with associated transients that pose …


Contributing To Engineering Colleges Students' Development Through Out-Of-Class Involvement: A Survey Of Chinese Private Colleges' Engineering Students, Wanlu Li May 2021

Contributing To Engineering Colleges Students' Development Through Out-Of-Class Involvement: A Survey Of Chinese Private Colleges' Engineering Students, Wanlu Li

Education (PhD) Dissertations

The purpose of this study was to investigate the primary characteristics of engineering college students’ involvement in out-of-class activities (OA) at one private college in China through the use of the translated and culturally adapted Chinese version of the Postsecondary Student Engagement Survey (PosSES 2.1). This study provides the statistical analyses of the survey data completed by 283 senior engineering students on their perceptions about their levels of involvement related to positive/negative outcomes students perceive and affective engagement. Data results showed all levels of involvement have a significant influence on positive outcomes. Besides, active involvement degree, hours, and types of …


Study Of Static And Dynamical Properties Of Complex Antiferroelectrics Materials, Kinnary Yogeshbhai Patel May 2021

Study Of Static And Dynamical Properties Of Complex Antiferroelectrics Materials, Kinnary Yogeshbhai Patel

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of the static and dynamical properties of the complex antiferroelectric materials using Effective Hamiltonian method and First principles calculations. In chapter 3, a novel elemental interatomic coupling in perovskite materials which bilinearly couples the antiferroelectric displacements of cations with the rotations of the oxygen octahedra. This new coupling explains a very complex crystal structure of prototypical antiferroelectric PbZrO3. My explanation provides a unified description of many other complex antipolar crystal structures in variety of perovskite materials, including the occurrence of incommensurate phases in some of them. In chapter 4, results and analysis …


Atomic Layer Deposition Of Sodium Fluoride Thin Films, Sara Kuraitis, Donghyeon Kang, Anil U. Mane, Hua Zhou, Jake Soares, Jeffrey W. Elam, Elton Graugnard May 2021

Atomic Layer Deposition Of Sodium Fluoride Thin Films, Sara Kuraitis, Donghyeon Kang, Anil U. Mane, Hua Zhou, Jake Soares, Jeffrey W. Elam, Elton Graugnard

Materials Science and Engineering Faculty Publications and Presentations

The need for advanced energy conversion and storage devices remains a critical challenge amid the growing worldwide demand for renewable energy. Metal fluoride thin films are of great interest for applications in lithium-ion and emerging rechargeable battery technologies, particularly for enhancing the stability of the electrode-electrolyte interface and thereby extending battery cyclability and lifetime. Reported within, sodium fluoride (NaF) thin films were synthesized via atomic layer deposition (ALD). NaF growth experiments were carried out at reactor temperatures between 175 and 250 °C using sodium tert-butoxide and HF-pyridine solution. The optimal deposition temperature range was 175–200 °C, and the resulting …