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Articles 1111 - 1140 of 4850

Full-Text Articles in Engineering

Microfabrication And Characterization Of Freestanding And Integrated Carbon Nanotube Thin Films, Derric Benjamin Syme Apr 2019

Microfabrication And Characterization Of Freestanding And Integrated Carbon Nanotube Thin Films, Derric Benjamin Syme

Theses and Dissertations

This work chronicles the fabrication of two unique thin films using carbon nanotubes. The first is a carbon film made primarily from vertically grown carbon nanotubes (CNTs) and rolled into lateral alignment. The second is an insulating film created by CNTs as a scaffolding to create a porous silica layer. Each topic represents a different method of utilizing CNTs for thin-film fabrication.Investigation of an entirely carbon thin film, comprised of aligned and laterally oriented carbon nanotubes was performed. The thin film was strengthened by deposition of amorphous carbon for a total thickness of <<> 5 µm. This thickness is thinner than …

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Analysis Of Distortion Transfer And Generation Through A Fan And A Compressor Using Full-Annulus Unsteady Rans And Harmonic Balance Approaches, Daniel Robert Soderquist Apr 2019

Analysis Of Distortion Transfer And Generation Through A Fan And A Compressor Using Full-Annulus Unsteady Rans And Harmonic Balance Approaches, Daniel Robert Soderquist

Theses and Dissertations

Understanding distortion transfer and generation through fan and compressor blade rows is able to assist in blade design and performance prediction. Using full annulus unsteady RANS simulations, the effects of distortion as it passes through the rotor of a transonic fan at five radial locations (10%, 30%, 50%, 70%, and 90% span) are analyzed. The inlet distortion profile is a 90-degree sector with a 15% total pressure deficit. Fourier distortion descriptors are used in this study to quantitatively describe distortion transfer and generation. Results are presented and compared for three operating points (near-stall, design, and choke). These results are used …

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Near Real-Time Flood Forecasts From Global Hydrologic Forecasting Models, Corey Nicholas Krewson Apr 2019

Near Real-Time Flood Forecasts From Global Hydrologic Forecasting Models, Corey Nicholas Krewson

Theses and Dissertations

This research assesses possible methods for extending the Streamflow Prediction Tool from a streamflow forecasting model to a flood extent forecasting model. This new flood extent forecasting model would allow valuable and easy to understand information be disseminated in a timely manner for flood preparation and flood response. The Height Above Nearest Drainage (HAND) method and AutoRoute method were considered for flood extent models but the HAND was the better option for its simple and quick computation as well as its viability on a global scale. Due to the importance of Digital Elevation Models (DEMs) in these flood extent models, …

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Mesoscale Modeling Of Shape Memory Alloys By Kinetic Monte Carlo–Finite Element Analysis Methods, Adam David Herron Apr 2019

Mesoscale Modeling Of Shape Memory Alloys By Kinetic Monte Carlo–Finite Element Analysis Methods, Adam David Herron

Theses and Dissertations

A coupled kinetic Monte Carlo – Finite Element Analysis (kMC–FEA) method is developed with a numerical implementation in the Scalable Implementation of Finite Elements at NASA (ScIFEN). This method is presented as a mesoscale model for Shape Memory Alloy (SMA) material systems. The model is based on Transition State Theory and predicts the nonlinear mechanical behavior of the 1st order solid–solid phase transformation between Austenite and Martensite in SMAs. The kMC–FEA modeling method presented in this work builds upon the work of Chen and Schuh [1, 2]. It represents a “bottom-up” approach to materials modeling and could serve as a …

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Estimating Phase Durations For Chloride-Induced Corrosion Damage Of Concrete Bridge Decks In Utah, Kaylee Dee Bateman Apr 2019

Estimating Phase Durations For Chloride-Induced Corrosion Damage Of Concrete Bridge Decks In Utah, Kaylee Dee Bateman

Theses and Dissertations

Chloride-induced deterioration of concrete bridge decks can be described in terms of three phases: 1) initiation of rebar corrosion, 2) rust formation and development of deck damage, and 3) accelerated deck damage towards structural failure. The first objective of this research was to investigate relationships among chloride concentration at the top mat of reinforcing steel, deck age, cover depth, and occurrence of delamination for concrete bridge decks with selected surface treatments and rebar types. Relating these factors can help establish greater understanding about the duration of each phase of the deterioration process. A second objective of this research was to …

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Skeletal Muscle Recovery And Vibration, Garrett Collier Jones Apr 2019

Skeletal Muscle Recovery And Vibration, Garrett Collier Jones

Theses and Dissertations

In the past decade there has been a significant increase in focus on the effect upper body vibration (UBV) has on the recovery of skeletal muscle after exercise-induced muscle damage. Recovery can be defined and investigated using a wide variety of methods. This study used three different measurements to track muscle recovery over 7 days following an exercise muscle damage protocol and applied vibration to a mathematical model. A visual analog scale (VAS) was used to measure muscle pain, a strain gauge was used to obtain maximum voluntary isometric contraction (MVIC) strength measurements, and shear wave elastography (SWE) represented muscle …

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Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert Apr 2019

Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert

Theses and Dissertations

Radio Astronomy, the study of distant objects in the radio spectrum, is set at defiance against all other users of the electromagnetic spectrum. Where traditional use would fill the electromagnetic spectrum with as much transmission and information as possible, Radio Astronomy would rather no man-made signals existed. Since that is not possible, they grumble and have to deal with unwanted transmissions impinging upon their instruments. I have demonstrated that subspace projection can remove these unwanted signals from Radio Astronomical data in post processing. I demonstrate it both on simulated data and on data taken from the Very Large Array radio …

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Molecular Methods For The Identification And Quantification Of Cyanobacteria In Surface Water Sources, Treyton Michael Moore Apr 2019

Molecular Methods For The Identification And Quantification Of Cyanobacteria In Surface Water Sources, Treyton Michael Moore

Theses and Dissertations

Geosmin is a strong musty-flavored organic compound that is responsible for many taste-and-odor events in surface drinking water sources like lakes and reservoirs. The taste threshold of geosmin for humans is lower than 10 ng/L. Traditional treatment methods will not remove geosmin to this level. Additional water treatment methods must be implemented to successfully remove the geosmin and its associated flavor and odor from drinking water. Furthermore, geosmin is produced by cyanobacteria somewhat sporadically, so it is difficult to predict when taste-and-odor events are going to occur. The difficulty involved with predicting geosmin events has led most water treatment facilities …

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Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger Apr 2019

Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger

Theses and Dissertations

This is one of the first time series studies of bacteria in soils supporting actively growing corn crops. Mathematically modeling bacteria population dynamics has the potential as a tool to more precisely assess the economic optimal nitrogen fertilizer rate for farmers. As a first step in this modeling effort, we examine the possibility that the bacteria population growth might be described by a dynamic model developed in the food sciences describing bacteria growth in food meant for human consumption. We make the assumption that air temperature above the soil can be used as an approximation for soil temperature. Also, because …

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Impact Of Pulse Length On The Accuracy Of Defect Depth Measurements In Pulse Thermography, James Pierce, Nathan B. Crane Apr 2019

Impact Of Pulse Length On The Accuracy Of Defect Depth Measurements In Pulse Thermography, James Pierce, Nathan B. Crane

Faculty Publications

Pulse thermography is a nondestructive testing method in which an energy pulse is applied to a surface while the surface temperature evolution is measured to detect sub surface defects and estimate their depth. This nondestructive test method was developed on the assumption of instantaneous surface heating, but recent work has shown that relatively long pulses can be used to accurately determine defect depth in polymers. This paper examines the impact of varying input pulse length on the accuracy of defect depth quantification as a function of the material properties. Simulations using both thermoplastics and metals show that measurement error is …

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An Analysis Of Decision Boundaries For Left-Turn Treatments, Michael Louis Adamson Apr 2019

An Analysis Of Decision Boundaries For Left-Turn Treatments, Michael Louis Adamson

Theses and Dissertations

The purpose of this project is to evaluate the safety and operational differences between three left-turn treatments: permitted, protected, and protected-permitted left-turn phasing. Permitted phasing allows vehicles to turn left after yielding to any opposing vehicles; protected phasing provides an exclusive phase for vehicles to turn left that does not allow opposing vehicles; and protected-permitted phasing combines the previous phasing alternatives, allowing vehicles to turn after yielding while also providing some green time for protected left-turns.As part of evaluating the differences between these left-turn treatments, crashes before and after the change at intersections that had experienced a permanent change from …

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Machine Learning Methods For Nanophotonic Design, Simulation, And Operation, Alec Michael Hammond Apr 2019

Machine Learning Methods For Nanophotonic Design, Simulation, And Operation, Alec Michael Hammond

Theses and Dissertations

Interest in nanophotonics continues to grow as integrated optics provides an affordable platform for areas like telecommunications, quantum information processing, and biosensing. Designing and characterizing integrated photonics components and circuits, however, remains a major bottleneck. This is especially true when complex circuits or devices are required to study a particular phenomenon.To address this challenge, this work develops and experimentally validates a novel machine learning design framework for nanophotonic devices that is both practical and intuitive. As case studies, artificial neural networks are trained to model strip waveguides, integrated chirped Bragg gratings, and microring resonators using a small number of simple …

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A Discovery Of Social Impact Categories For The Sustainable Design Of Engineered Products And Their Consideration By Industry Professionals, Andrew Taylor Pack Apr 2019

A Discovery Of Social Impact Categories For The Sustainable Design Of Engineered Products And Their Consideration By Industry Professionals, Andrew Taylor Pack

Theses and Dissertations

Sustainable design is often practiced and assessed through the consideration of three essential areas: economic sustainability, environmental sustainability, and social sustainability. For even the simplest of products, the complexities of these three areas and their trade-offs cause decision making transparency to be lost in most practical situations. Additionally, the models and tools available to consider social sustainability are severely underdeveloped. This thesis is separated into three parts: 1) a design tool to consider all three aspects of sustainability simultaneously, 2) a literature survey to characterize social impact as it relates to products, and 3) interviews with engineering professionals regarding how …

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Increased Cyclist Safety Using An Embedded System, Matthew Ryan Heydorn Apr 2019

Increased Cyclist Safety Using An Embedded System, Matthew Ryan Heydorn

Theses and Dissertations

In order to reduce bicycle-vehicle collisions, we design and implement a cost effectiveembedded system to warn cyclists of approaching vehicles. The system uses an Odroid C2 singleboard computer (SBC) to do vehicle and lane detection in real time using only vision. The system warns cyclist are warned of approaching cars using both a smartphone app and an LED indicator. Due to the limited performance of the Odroid C2 and other low power and low cost SBCs,we found that existing detection algorithms run either too slowly or do not have sufficient accuracy to be practical. Our solution to these limitations is …

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Modeling Piezoresistive Effects In Flexible Sensors, Marianne E. Clayton Apr 2019

Modeling Piezoresistive Effects In Flexible Sensors, Marianne E. Clayton

Theses and Dissertations

This work describes a model of the piezoresistive behavior in nanocomposite sensors. These sensors are also called flexible sensors because the polymer matrix allows for large deformations without failure. The sensors have conductive nanoparticles dispersed through an insulative polymer matrix. The insulative polymer gaps between nanoparticles are assumed to be possible locations for electron tunneling. When the distance between two nanoparticles is small enough, electrons can tunnel from one nanoparticle to the next and ultimately through the entire sensor. The evolution of this gap distance with strain is important to understand the overall conductivity of the strain sensor. The gap …

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Statistical Analysis And Extraction Of Quantitative Data From Elliptical-Signal-Model Bssfp Mri, Meredith Ireene Dupaix Taylor Apr 2019

Statistical Analysis And Extraction Of Quantitative Data From Elliptical-Signal-Model Bssfp Mri, Meredith Ireene Dupaix Taylor

Theses and Dissertations

Osteoarthritis is the most common type of arthritis, and is characterized by the loss of articular cartilage in a joint. This eventually leads to painful bone on bone interactions. Since the loss of cartilage is permanent, the main treatment for this disease is pain management until a full joint replacement is needed. To test new potential treatments a consistent way to measure cartilage thickness is needed. The current standard used in the knee to represent cartilage uses joint space width measured from x-rays. This measurement is highly variable, and does not directly show cartilage. Unlike x-rays, magnetic resonance imaging (MRI) …

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Aerodynamic Design Optimization Of A Locomotive Nose Fairing For Reducing Drag, Chad Lamar Stucki Apr 2019

Aerodynamic Design Optimization Of A Locomotive Nose Fairing For Reducing Drag, Chad Lamar Stucki

Theses and Dissertations

Rising fuel cost has motivated increased fuel efficiency for freight trains. At cruising speed,the largest contributing factor to the fuel consumption is aerodynamic drag. As a result of stagnationand flow separation on and around lead and trailing cars, the first and last railcars experiencegreater drag than intermediate cars. Accordingly, this work focused on reducing drag on lead locomotivesby designing and optimizing an add-on nose fairing that is feasible for industrial operation.The fairing shape design was performed via computational fluid dynamic (CFD) software.The simulations consisted of two in-line freight locomotives, a stretch of rails on a raised subgrade,a computational domain, and …

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Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson Mar 2019

Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson

Undergraduate Honors Theses

The advent of new technologies such as eVTOL vehicles is exciting. The development of fast aerodynamics models incorporating stall is one small step on the road to realizing such concepts by improving the speed of design optimization algorithms. To this end, a modified vortex lattice model was developed based on one reported by dos Santos and Marques [4]. The model was validated against experimental data found in the literature. Making use of its stall capabilities, a sample study was performed to test for any coupling effect between aspect ratio and taper ratio. This was done by calculating the lift curve …

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Steering System For Sae Baja, Dallin Colgrove Mar 2019

Steering System For Sae Baja, Dallin Colgrove

Undergraduate Honors Theses

This thesis is to study the different types of steering geometry for the BYU Baja vehicle. The main steering geometries of study are Ackermann and parallel steering geometries. Ackermann steering geometry is ideal for low speed turns. During low speed turns Ackermann steering performs better than parallel steering due to a smaller radius of turn. Parallel steering ideally is better for high speed turns, because with parallel steering the slip angle is smaller than that of Ackermann geometry. A recommendation is made to the BYU Baja team to use Ackermann steering, but still do some more analysis of parallel steering …

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Implementation Of Augmented Reality In Sae Mini Baja, Brady S. Hales Mar 2019

Implementation Of Augmented Reality In Sae Mini Baja, Brady S. Hales

Undergraduate Honors Theses

Engineers often encounter difficulties in connecting digital data with its physical counterpart. This applies to processing and interpreting data as well as effectively communicating design ideas and considerations. Augmented reality has the ability to solve these problems by overlaying digital data on a physical object. This allows engineers to further explore design considerations such as ergonomics as well as communicate data such as, Finite Element Analysis. This communication may be realized in discussing and collaborating with colleagues, as well as to judges in design reviews. Augmented reality is beneficial in these cases and is further explored in this thesis, utilizing …

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Developing A Method To Identify Horizontal Curve Segments With High Crash Occurrences Using The Haf Algorithm, Joseph Stuart Browning Mar 2019

Developing A Method To Identify Horizontal Curve Segments With High Crash Occurrences Using The Haf Algorithm, Joseph Stuart Browning

Theses and Dissertations

Crashes occur every day on Utah’s roadways. Curves can be particularly dangerous as they require driver focus due to potentially unseen hazards. Often, crashes occur on curves due to poor curve geometry, a lack of warning signs, or poor surface conditions. This can create conditions in which vehicles are more prone to leave the roadway, and possibly roll over. These types of crashes are responsible for many severe injuries and a few fatalities each year, which could be prevented if these areas are identified. This highlights a need for identification of curves with high crash occurrences, particularly on a network-wide …

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Implementing An Iiot Core System For Simulated Intelligent Manufacturing In An Educational Environment, Andrew Craig Nemrow Mar 2019

Implementing An Iiot Core System For Simulated Intelligent Manufacturing In An Educational Environment, Andrew Craig Nemrow

Theses and Dissertations

In this new digital age, efficiency, quality and competition are all increasing rapidly as companies leverage the Industrial Internet of Things (IIoT). However, while industrial innovation moves at a faster and faster pace, educational institutions have lagged in the development of the curriculum and environment needed to support further development of the IIoT. To fully realize the potential of the IIoT in the manufacturing sector educational institutions must support the technological training and education rigor demanded to instill the skills and thought leadership to move the industry forward. The purpose of this research is to provide an IIoT core system …

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Strain Path Effect On Austenite Transformation And Ductility In Tbf 1180 Steel, Parker Kenneth Gibbs Mar 2019

Strain Path Effect On Austenite Transformation And Ductility In Tbf 1180 Steel, Parker Kenneth Gibbs

Theses and Dissertations

TBF 1180 steel was studied under various conditions focusing on the correlation of ductility and amount of retained austenite. Samples were prepared from sheet stock and then strained using limiting dome height tooling (LDH), a standard uniaxial test frame, and a tensile stage for use in an electron microscope. The steel was observed in plane, biaxial, and uniaxial strain to determine its effect on retained austenite transformation and ultimately, ductility. Retained austenite was observed using a scanning electron microscope (SEM) equipped with an electron backscatter detector (EBSD) to distinguish the different phases present. Initial austenite levels were around 5% by …

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Neutron Beam Testing Methodology And Results For A Complex Programmable Multiprocessor Soc, Jordan Daniel Anderson Mar 2019

Neutron Beam Testing Methodology And Results For A Complex Programmable Multiprocessor Soc, Jordan Daniel Anderson

Theses and Dissertations

The Xilinx Multiprocessor System-on-Chip (MPSoC) is a complex device that uses 16nm FinFET technology to combine multiple processors, a large amount of FPGA resources, and many I/O interfaces on a single chip die. These features make the MPSoC a high-performance and architecturally flexible device. The potential computing power makes the MPSoC ideal for many embedded applications including terrestrial and space applications. The MPSoC, however, does not have extensive radiation history as many other devices have. The extent of the effect that ionized particles may have on the MPSoC is not well established. To solve this problem, neutron radiation testing can …

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Pedestrian Walking Speeds At Signalized Intersections In Utah, Jordi Jordan Berrett Mar 2019

Pedestrian Walking Speeds At Signalized Intersections In Utah, Jordi Jordan Berrett

Theses and Dissertations

The 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD) recommends a pedestrian walking speed of 3.5 feet per second for use in the timing of pedestrian clearance intervals at signalized intersections (reduced from 4.0 feet per second in the 2003 edition). Jurisdictions across the state of Utah continue to maintain pedestrian walking speeds of 4.0 feet per second for normal intersections with guidance on engineering judgement for areas where a lower pedestrian walking speed should be considered. In 2018, it was decided that the current state guidance with regard to pedestrian walking speeds be evaluated for any …

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Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson Mar 2019

Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson

Theses and Dissertations

The development of phased array antenna systems requires considerable resources and time. Due to this constraint, the Naval Air Command (NAVAIR) needs a phased array that can be physically reconfigured to meet the demands of multiple missions without added development time or cost. This work develops and demonstrates a solution to this problem by implementing an adaptive calibration approach to the development of electronically steerable antennas (ESAs). In contrast to previous analog adaptive beamformer systems, this system allows for an arbitrary antenna configuration with a variable number of antenna elements and locations. A simulation model of arbitrary phased array configurations …

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Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati Mar 2019

Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati

Theses and Dissertations

A series of silver-promoted, 20 wt% cobalt Fischer-Tropsch synthesis (FTS) catalysts supported on an alumina modified with 5 wt% silica were prepared using two methods: traditional incipient wetness impregnation (IWI) and a new solvent-deficient precipitation (SDP) technique. Catalysts containing silver promoter concentrations of 0.3, 0.6, 1.2, and 2.5 wt% were prepared using each of the two methods. Silver improved the reducibility of the cobalt significantly, lowering reduction temperatures by up to 100°C, and increasing the extent of reduction by up to 35%. Further, in both preparation methods, changing the silver loading altered the cobalt dispersion. The smallest Co crystallite size …

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Characterization Of Mechanical Properties Of Thin-Film Li-Ion Batteryelectrodes From Laser Excitation And Measurements Ofzero-Group Velocity Resonances, Jing Yao Mar 2019

Characterization Of Mechanical Properties Of Thin-Film Li-Ion Batteryelectrodes From Laser Excitation And Measurements Ofzero-Group Velocity Resonances, Jing Yao

Theses and Dissertations

The mechanical properties of thin-film Li-ion battery electrodes are controlled by the micro structure of the constituent materials. In this work, a non-contact and non-destructive measurement of the mechanical properties of electrode films is performed by measurement of zero group velocity (ZGV) resonances. The ZGV Lamb wave modes of a solid bi-layer consisting of a thin metallic layer and a thin compliant coating layer are shown to be dependent on the Young's moduli, thicknesses, densities and Poisson ratios of the layers. Theoretical models are used to quantify the sensitivity of the ZGV resonances to changes in mechanical properties. Experimental ZGV …

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Complexity Of Establishing Industrial Connectivity For Small And Medium Manufacturers With And Without Use Of Industrial Innovation Platforms, Brian Dale Russell Mar 2019

Complexity Of Establishing Industrial Connectivity For Small And Medium Manufacturers With And Without Use Of Industrial Innovation Platforms, Brian Dale Russell

Theses and Dissertations

The manufacturing industry is continuously evolving as new practices and technology are adopted to improve productivity and remain competitive. There have been three well established manufacturing revolutions in recent history and some say that the fourth is occurring currently by the name of Smart Manufacturing, Indusrie 4.0, and others. This latest manufacturing revolution is highly dependent on industrial connectivity. This research aims to gage the ability of Industrial Innovation Platforms (IIPs) to reduce complexity of implementing base-line industrial connectivity for small and medium-sized enterprises (SMEs). The results of this study would be especially relevant to decision makers in industrial SMEs …

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Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell Feb 2019

Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell

Theses and Dissertations

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric.
Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can …

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