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Articles 1 - 30 of 92
Full-Text Articles in Engineering
Experimental And Modeling Of Biomass Char Gasification, Ruochen Wu
Experimental And Modeling Of Biomass Char Gasification, Ruochen Wu
Theses and Dissertations
This investigation provides a comprehensive experimental dataset and kinetic model for biomass gasification, over a wide temperature range (1150-1350 °Ï¹) in CO2, H2O and the combination of these two reactant gases over the mole fraction ranges of 0 to 0.5 for H2O and 0 to 0.9 for CO2. The data come from a unique experimental facility that tracks continuous mass loss rates for poplar wood, corn stover and switchgrass over the size range of 6-12.5 mm. In addition, the data include char size, shape, surface and internal temperature and discrete measurements of porosity, total surface area, pore size distribution and …
Root Cause Analysis And Classification Of Single Point Failures In Designs Applying Triple Modular Redundancy In Sram Fpgas, James D. Swift
Root Cause Analysis And Classification Of Single Point Failures In Designs Applying Triple Modular Redundancy In Sram Fpgas, James D. Swift
Theses and Dissertations
Radiation effects encountered in space or aviation environments can affect the configuration bits in Field Programmable Gate Arrays (FPGA) causing errors in FPGA output. One method of increasing FPGA reliability in radiation environments includes adding redundant logic to mask errors and allow time for repair. Despite the redundancy added with triple modular redundancy (TMR) and configuration scrubbing there exist some configuration bits that individually affect multiple TMR domains causing errors in FPGA output. A new tool called DeBit is introduced that identifies hardware resources associated with a single bit failure. This tool identifies a novel failure mode involving global routing …
Blast-Induced Liquefaction And Downdrag Development On A Micropile Foundation, Cameron Mark Lusvardi
Blast-Induced Liquefaction And Downdrag Development On A Micropile Foundation, Cameron Mark Lusvardi
Theses and Dissertations
Frequently, deep foundations extend through potentially liquefiable soils. When liquefaction occurs in cohesionless soils surrounding a deep foundation, the skin-friction in the liquefied layer is compromised. After cyclical forces suspend and pore pressures dissipate, effective stress rebuilds and the liquefied soil consolidates. When the settlement of the soil exceeds the downward movement of the foundation, downdrag develops. To investigate the loss and redevelopment of skin-friction, strain was measured on an instrumented micropile during a blast-induced liquefaction test in Mirabello, Italy. The soil profile where the micropile was installed consisted of clay to a depth of 6m underlain by a medium …
Instructional Case Studies In The Field Of Windfarm Optimization, N. Francesco Baker
Instructional Case Studies In The Field Of Windfarm Optimization, N. Francesco Baker
Theses and Dissertations
Wind farm layout optimization is a multidisciplinary undertaking, requiring students and researchers to integrate many skillsets in order to optimize turbine placement. There is currently a lack of useful benchmarking exercises for participants in the field to compare the efficacy of their methods. This work details the construction and completion of a set of four case studies meant to satisfy this need, with the hope of providing some insight into useful layout optimization approaches. These case studies are intended to also serve as instructive introductory exercises with which newcomers researching wind energy may incrementally practice and increase their abilities.The first …
The Impact Of Calendering On The Electronic Conductivity Heterogenity Of Lithium-Ion Electrode Films, Emilee Elizabeth Hunter
The Impact Of Calendering On The Electronic Conductivity Heterogenity Of Lithium-Ion Electrode Films, Emilee Elizabeth Hunter
Theses and Dissertations
Advancements in Li-ion batteries are needed especially for the development of electric vehicles and stationary energy storage. Prior research has shown mesoscale variations in electrode electronic conductive properties, which can cause capacity loss and uneven electrochemical behavior of Li-ion batteries. A micro-four-line probe (μ4LP) was used to measure electronic conductivity and contact resistance over mm-length scales in that prior work. This work describes improvements to overcome the challenge of unreliable surface contact between theμ4LP and the sample. Ultimately a second generation flexible probe called the micro-radial-surface probe (μ4LP) was designed and produced. The test fixture was also optimized to obtain …
Development Of A Management Guide For Concrete Bridge Decks In Utah, Tenli Waters Emery
Development Of A Management Guide For Concrete Bridge Decks In Utah, Tenli Waters Emery
Theses and Dissertations
The objectives of this research were to 1) investigate bridge deck condition assessment methods used in the field and laboratory, methods of managing bridge decks, and methods for estimating remaining bridge deck service life using computer models through a comprehensive literature review on these subjects; 2) collect and analyze field data from representative concrete bridge decks in Utah; and 3) develop a decision tree for concrete bridge deck management in Utah. As a result of the literature review performed for objective 1, a synthesis of existing information about condition assessment, bridge deck preservation and rehabilitation, bridge deck reconstruction, and estimating …
Signal Transport And Rf Over Fiber Design For Alpaca, Erich Johannes Nygaard
Signal Transport And Rf Over Fiber Design For Alpaca, Erich Johannes Nygaard
Theses and Dissertations
The design of the RF over fiber signal transport system for the ALPACA receiver is described, with particular attention to the strict noise requirements as well as dynamic range considerations. Also discussed are analytical tools for analyzing dynamic range in the context of RFI-rich radio astronomy observational settings, including formulas for maximum interference to noise ratios and a simulation framework for predicting distortion levels. Phase and gain stability measurements of the signal transport system are presented, including the effects of the multi-strand armored fiber optic cable. The resulting system meets design requirements, with equivalent noise temperature below 900 K in …
Frameworks For Part Generation In Multiple Cad Systems And For Cad Simulation With Multiple Users, Jonathan Edwin Sadler
Frameworks For Part Generation In Multiple Cad Systems And For Cad Simulation With Multiple Users, Jonathan Edwin Sadler
Theses and Dissertations
Companies often require designers to work with and operate between different computer-aided design (CAD) systems. To interoperate between these systems, a neutral design standard for CAD models is needed that allows for generation, customization, and parameterization. Current standards often fail to incorporate file history and design intent. The research proposes a simplified, neutral design format that can be used to generate models in different CAD systems. The format proposes additional functionality not yet found in existing neutral formats or scripts. The system was tested by generating models in both NX and CATIA, then comparing the models for accuracy, flexibility, and …
Effects Of Conformal Cooling Channels On Additively Manufactured Injection Molding Tooling, Tyler Blaine Whatcott
Effects Of Conformal Cooling Channels On Additively Manufactured Injection Molding Tooling, Tyler Blaine Whatcott
Theses and Dissertations
This study focuses on the cycle-averaged mold temperature of additively manufactured injection molding tooling and how it is affected by conformal cooling channels. This was done by producing a benchmark mold out of Digital ABS produced by Stratasys, an acrylic based photopolymer, which was then used to produce injection molded parts until tool failure. Another, more cost-effective material, High Temp Resin produced by Formlabs, another acrylic based photopolymer, was also tested but yielded very little success. Then the mold design was altered by adding conformal cooling channels and again tested by producing injection molded parts while tracking the mold temperature. …
Lateral Resistance Of 24-Inch Statically Loaded And 12.75-Inch Cyclically Loaded Pipe Piles Near A 20-Ft Mechanically Stabilized Earth (Mse) Wall, Addison Joseph Wilson
Lateral Resistance Of 24-Inch Statically Loaded And 12.75-Inch Cyclically Loaded Pipe Piles Near A 20-Ft Mechanically Stabilized Earth (Mse) Wall, Addison Joseph Wilson
Theses and Dissertations
Installing load bearing piles within the reinforcement zone of mechanically stabilized earth (MSE) retaining walls is common practice in the construction industry. Bridge abutments are often constructed in this manner to adapt to increasing right-of-way constraints, and must be capable of supporting horizontal loads imposed by, traffic, earthquakes, and thermal expansion and contraction. Previous researchers have concluded that lateral pile resistance is reduced when pile are placed next to MSE walls but no design codes have been established to address this issue. Full –scale testing of statically applied lateral loads to four 24”x0.5” pipe piles, and cyclically applied lateral load …
The Integration Of Iterative Convergent Photogrammetric Models And Uav View And Path Planning Algorithms Into The Aerial Inspection Practices In Areas With Aerial Hazards, Michael James Freeman
The Integration Of Iterative Convergent Photogrammetric Models And Uav View And Path Planning Algorithms Into The Aerial Inspection Practices In Areas With Aerial Hazards, Michael James Freeman
Theses and Dissertations
Small unmanned aerial vehicles (sUAV) can produce valuable data for inspections, topography, mapping, and 3D modeling of structures. Used by multiple industries, sUAV can help inspect and study geographic and structural sites. Typically, the sUAV and camera specifications require optimal conditions with known geography and fly pre-determined flight paths. However, if the environment changes, new undetectable aerial hazards may intersect new flight paths. This makes it difficult to construct autonomous flight path missions that are safe in post-hazard areas where the flight paths are based on previously built models or previously known terrain details. The goal of this research is …
Photoacoustic Co2 Detection In Biomass Cookstove Applications, Jacob Matthew Thomas
Photoacoustic Co2 Detection In Biomass Cookstove Applications, Jacob Matthew Thomas
Theses and Dissertations
Billions of people use biomass burning cookstoves in their homes and suffer serious health repercussions. Additionally, global warming is exacerbated by cookstove emissions containing greenhouse gases and particulate matter. Improved cookstoves (ICSs) mitigate the problem, but accurate and affordable emission gas measurements, particularly of Carbon Dioxide (CO2) and Carbon Monoxide (CO), are required in order to confidently declare ICSs cleaner burning than traditional cookstoves. The aim of this research is to assess the suitability of photoacoustic (PA) CO2 detection technology for cookstove emissions monitoring. The designs of several longitudinally resonant, photoacoustic, LED, CO2 sensors of varying levels of functionality are …
Exploration Into The Use Of A Software Defined Radio As A Low-Cost Radar Front-End, Andrew Michael Monk
Exploration Into The Use Of A Software Defined Radio As A Low-Cost Radar Front-End, Andrew Michael Monk
Theses and Dissertations
Inspection methods for satellites post-launch are currently expensive and/or dangerous. To address this, BYU, in conjunction with NASA, is designing a series of small satellites called CubeSATs. These small satellites are designed to be launched from a satellite and to visually inspect the launching body. The current satellite revision passively tumbles through space and is appropriately named the passive inspection cube satellite (PICS). The next revision actively maintains translation and rotation relative to the launching satellite and is named the translation, rotation inspection cube satellite (TRICS). One of the necessary sensors aboard this next revision is the means to detect …
Tidally Generated Internal Waves From Asymmetric Topographies, Kyle Jeffrey Hakes
Tidally Generated Internal Waves From Asymmetric Topographies, Kyle Jeffrey Hakes
Theses and Dissertations
Internal waves are generated in stratified fluids, like the ocean, where density increases with depth. Tides are one of the major generation mechanisms of internal waves. As the tides move water back and forth over underwater topography, internal waves can be generated. The shape of the topography plays a major part in the properties of the generated internal wave and the type of wave and energy is known for multiple symmetric topographies, such as Gaussian or sinusoidal. In order to further understand the effects topographic shape plays, the effect of asymmetry on internal waves is investigated. First, two experimental methods …
Columbine And The Myth Of The Juvenile Superpredator, Christopher M. Mosqueda
Columbine And The Myth Of The Juvenile Superpredator, Christopher M. Mosqueda
Theses and Dissertations
Mass media has great influence over its audience. When a sensational story hits the news waves, the general public's attention is instantly riveted to the television screen. News stories that involve the deaths of innocent people often create a culture of fear, fuel false narratives, and scatter misinformation. In fact, this culture of fear, coupled with misleading information, created the myth of the juvenile superpredator, a phrase coined by DiIulio in the early 1990s. The stereotyped superpredator was a homicidal, uncontrollable youth hiding within areas where crime and violence are rare. In particular, this myth was propagated following the massacre …
Characterization Of Slip Activity In The Presence Of Slip Bands Using Surface-Based Microscopy Techniques, Ryan Aaron Sperry
Characterization Of Slip Activity In The Presence Of Slip Bands Using Surface-Based Microscopy Techniques, Ryan Aaron Sperry
Theses and Dissertations
Further understanding of mesoscale slip mechanics is crucial to future development of polycrystalline metals with improved performance. The research contained within this thesis aims to characterize localized mesoscale slip on slip bands further through two studies. First, a comprehensive comparison of slip system identification techniques was carried out to further validate each method as well as compare advantages and disadvantages of each. Second, slip bands in the presence of grain boundaries were studied to better characterize the dislocation content and behavior. In the first study, the use of SEM-DIC, AFM, ECCI, and HR-EBSD to characterize slip-system activity was assessed on …
Two-Photon 3-Dimensional Photoelectrochemical Etching Of Single Crystal Silicon Carbide, Peter Robert Nyholm
Two-Photon 3-Dimensional Photoelectrochemical Etching Of Single Crystal Silicon Carbide, Peter Robert Nyholm
Theses and Dissertations
This thesis presents the first use of a novel direct-write, non-line-of-sight, two-photon photoelectrochemical etching technique for etching of single crystal silicon carbide substrates. The use of this technique has resulted in structuring of 3-dimensional structures in high quality single crystal silicon carbide wafers. The 3-dimensional structures demonstrated cannot be formed by any single or combination of traditional silicon carbide machining techniques. This thesis outlines the development of the optical, electrical, and diagnostic components required to achieve two-photon photoelectrochemical etching in silicon carbide. The diagnostic sub-assemblies --a single pixel confocal detector assembly and an in-situ optical microscope assembly-- and their design …
Molybdenum Deposition And Dissolution In Ethaline With The Use Of Fluoride Salts, Ethan Mitchel Gunnell
Molybdenum Deposition And Dissolution In Ethaline With The Use Of Fluoride Salts, Ethan Mitchel Gunnell
Theses and Dissertations
This work demonstrates the deposition of molybdenum in a deep eutectic solvent for the first time, and explores the processes needed for electrorefining of molybdenum. The electrochemical and transport behavior of chloride-coordinated molybdenum in ethaline was initially studied to determine if deposition was possible. Cyclic voltammetry was used to show that MoCl5 added to ethaline exhibits quasi-reversible behavior. Both the measured transfer coefficient and the precipitation of MoCl3 suggest that the reduction of MoCl5 in ethaline is a two-electron transfer reaction where the oxidation state of molybdenum in the product is Mo(III). No deposit was formed with the use of …
Improvements In Optical Trap Displays, R. Wesley Rogers
Improvements In Optical Trap Displays, R. Wesley Rogers
Theses and Dissertations
This thesis improves on the design of the Optical Trap Display (OTD), presented in 2018 [1]. Contributions include: real time animation; single beam, multiparticle suspension, point primitive anisotropic scattering, and virtual image approximation. First, real time animation was demonstrated on the OTD for the first time in full color at up to 30Hz refresh. Second, multi-particle systems allow for scaling of the display by a multiplicative factor, potentially up to orders of magnitude greater than the first OTD. Third, anisotropic scattering of point primitives was shown for individual suspended particles and multiple simultaneously suspended particles. Fourth, virtual images have been …
Modular 3d Printer System Software For Research Environments, Clayton D. Ramstedt
Modular 3d Printer System Software For Research Environments, Clayton D. Ramstedt
Theses and Dissertations
The Nordin group at Brigham Young University has been focused on developing 3D printing technology for fabrication of lab-on-a-chip (microfluidic) devices since 2013. As we showed in 2015, commercial 3D printers and resins have not been developed to meet the highly specialized needs of microfluidic device fabrication. We have therefore created custom 3D printers and resins specifically designed to meet these needs. As part of this development process, ad hoc 3D printer control software has been developed. However, the software is difficult to modify and maintain to support the numerous experimental iterations of hardware used in our custom 3D printers. …
Gradient-Based Layout Optimization Of Large Wind Farms: Coupled Turbine Design, Variable Reduction, And Fatigue Constraints, Andrew P. J. Stanley
Gradient-Based Layout Optimization Of Large Wind Farms: Coupled Turbine Design, Variable Reduction, And Fatigue Constraints, Andrew P. J. Stanley
Theses and Dissertations
Wind farm layout optimization can greatly improve wind farm performance. However, past wind farm design has been limited in several ways. Wind farm design usually assumes that all the turbines throughout the farm should be exactly the same. Oftentimes, the location of every turbine is optimized individually, which is computationally expensive. Furthermore, designers fail to consider turbine loads during layout optimization. This dissertation presents four studies which provide partial solutions to these limitations and greatly improve wind farm layout optimization. Two studies explore differing turbine designs in wind farms. In these studies, Wind farm layouts are optimized simultaneously with turbine …
Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow
Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow
Theses and Dissertations
This work investigates the material properties and production parameters of carbon infiltrated carbon nanotube structures (CI-CNT's). The impact of non homogeneous infiltration and the porosity of cross section regions, coupled with changes in designed geometry, in this case beam width, on the density and modulus of elasticity are compared. Three potential geometric models of beam cross section are proposed and evaluated. 3-point bending, SEM images, and numerical optimization are used to assess the validity of each model and the implications they have for future CI-CNT material applications. Carbon capping near exterior beam surfaces is observed and determined to be a …
Gas Chromatography Micro-Chip With High Temperature Interface And Silk Screen Heaters, Carlos R. Vilorio
Gas Chromatography Micro-Chip With High Temperature Interface And Silk Screen Heaters, Carlos R. Vilorio
Theses and Dissertations
There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low …
Improved Analysis Techniques For Scatterometer Wind Estimation, Gregory Dallin Schachterle
Improved Analysis Techniques For Scatterometer Wind Estimation, Gregory Dallin Schachterle
Theses and Dissertations
In this thesis, three improved analysis techniques for scatterometer wind estimation are presented. These techniques build upon previous methods that help validate scatterometer data. This thesis examines the theory connecting the 1D and 2D kinetic energy spectra and uses QuikSCAT data to measure the 2D kinetic energy spectrum of ocean winds. The measured 2D kinetic energy spectrum is compared to the traditional 1D kinetic energy spectrum. The relationship between the 2D kinetic energy spectra and the 1D kinetic energy spectra confirms findings from previous studies that ocean winds modeled in 2D are isotropic and nondivergent. The 1D and 2D kinetic …
Assessing The Effects Of Reconstruction On The Commercial And Civil Construction Industry Following Hurricane Maria In Puerto Rico, Timothy Jafek Barrett-Rodriguez
Assessing The Effects Of Reconstruction On The Commercial And Civil Construction Industry Following Hurricane Maria In Puerto Rico, Timothy Jafek Barrett-Rodriguez
Theses and Dissertations
In September 2017 Hurricane Maria made landfall on the U.S territory island of Puerto Rico, causing substantial damage to the already weakened infrastructure and other aspects of the built environment. This research attempted to identify the challenges and opportunities that have been encountered within the Puerto Rican commercial and civil construction industry during the first year of reconstruction, post-Hurricane Maria. This was done by identifying the effects of the storm as well as the strategies of construction companies involved in the reconstruction process. The study used the events occurring after the passing of the hurricane as a case study to …
Lateral Resistance Of Grouped Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Zachary Paul Farnsworth
Lateral Resistance Of Grouped Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Zachary Paul Farnsworth
Theses and Dissertations
A team from Brigham Young University and I performed full-scale lateral load tests on individual and grouped 12.75x0.375 inch pipe piles spaced at varying distances behind an MSE wall. The individually loaded pile which acted as a control was spaced at 4.0 pile diameters from the wall face, and the three grouped piles which were loaded in unison were spaced at 3.0, 2.8, and 1.8 pile diameters from the wall face and transversely spaced at 4.7 pile diameters center-to-center. The purpose of these tests was to determine the extent of group effects on lateral pile resistance, induced loads in soil …
Technology And Tactics As Dimensions Of Design: Explicit Representation Of User Actions In The Product Design Space, Tyler Stapleton
Technology And Tactics As Dimensions Of Design: Explicit Representation Of User Actions In The Product Design Space, Tyler Stapleton
Theses and Dissertations
The initial phases of the design process -- including interactions with stakeholders, ideation of concept candidates, and the selection of the best candidates --- have a large impact on the success of a project as a whole. Much of the value generated during these phases comes from the designers' exploration of the design space as they create concepts for the final solution. Unfortunately, an entire dimension of the design space is often ignored during the initial phases of the design process -- the tactics dimension. Engineers tend to emphasize the design of technology in their work, while paying less attention …
Characterization And Optimization Of An Image Charge Detector For The Measurement Of Martian Dust, Jace Rozsa
Characterization And Optimization Of An Image Charge Detector For The Measurement Of Martian Dust, Jace Rozsa
Theses and Dissertations
Image charge detector (ICD) technology has existed for decades. However, not until recently has an ICD been proposed for use in space exploration, specifically for studying the characteristics of the dust on Mars. Characterizing the dust on Mars is crucial for designing equipment to aid manned missions. It also improves our understanding of Mars' climate and weather systems. An ICD utilizing printed circuit board (PCB) electrodes, coupled with a custom differential amplifier, is best suited for this type of measurement because of its light weight, simplicity, and noise performance. The noise floor of our particular amplifier is measured to be …
A Framework For Simulating And Analyzing Multi-Uav Persistent Search And Retrieval With Stochastic Target Appearance, Ryan David Day
A Framework For Simulating And Analyzing Multi-Uav Persistent Search And Retrieval With Stochastic Target Appearance, Ryan David Day
Theses and Dissertations
In recent years, advances in small unmanned aerial vehicle (UAV) technology have transformed the use cases of these aircraft from hobby flying to industrial and business applications. These maneuverable, easily deployed tools can be retrofitted with a myriad of sensors and equipment, which make them suitable to perform a variety of specialized tasks. With increasing UAV capabilities, the function of small UAVs can be extended from pure monitoring or surveillance to the dual objective of monitoring an environment for events and addressing the events in some way. This thesis seeks to explore a subdomain of the dual objective problem described, …
Linbo3 Waveguide Modulators: A Gateway To Realizing Holovideo Technology, Jeffrey Christopher Leach
Linbo3 Waveguide Modulators: A Gateway To Realizing Holovideo Technology, Jeffrey Christopher Leach
Theses and Dissertations
In this dissertation, I will present the various work I have accomplished in regards to the design, simulation, and fabrication of holovideo and holodeck display technology. This includes: 1) design and analysis of a wavelength division multiplexing LiNbO3 waveguide device, 2) loss characterization and reduction (by way of reverse proton exchange) 3) design of a curved, near-eye AR display, and 4) a basis for acoustic holodeck technology (meant to service a system built from our optical devices). All these accomplishments represent, in concert, a manifestation of LiNbO3's capacity to serve as the building material central to modern holovideo displays. It …