Engineering Commons^™

An Investigation Of The Impact Of A Flipped Classroom Instructional Approach On High School Students' Content Knowledge And Attitudes Toward The Learning Environment, Matthew R. Bell

Theses and Dissertations

The idea of the “flipped classroom” is a relatively new concept in education that has become increasingly popular. Instructors who flip their classrooms reverse the roles of school work and homework by recording video lectures for students to watch before coming to class. Students then work on their homework in the classroom while the instructor is present to help them. Very little research has been done on the effectiveness of the flipped classroom to determine if students can perform better on exams by learning in a flipped classroom environment, especially for high school demographics. The purpose of this research is …

Deformation Twin Nucleation And Growth Characterization In Magnesium Alloys Using Novel Ebsd Pattern Analysis And Machine Learning Tools, Travis Michael Rampton

Theses and Dissertations

Deformation twinning in Magnesium alloys both facilitates slip and forms sites for failure. Currently, basic studies of twinning in Mg are facilitated by electron backscatter diffraction (EBSD) which is able to extract a myriad of information relating to crystalline microstructures. Although much information is available via EBSD, various problems relating to deformation twinning have not been solved. This dissertation provides new insights into deformation twinning in Mg alloys, with particular focus on AZ31. These insights were gained through the development of new EBSD and related machine learning tools that extract more information beyond what is currently accessed.The first tool relating …

The Programmatic Generation Of Discrete-Event Simulation Models From Production Tracking Data, Christopher Rand Smith

Theses and Dissertations

Discrete-event simulation can be a useful tool in analyzing complex system dynamics in various industries. However, it is difficult for entry-level users of discrete-event simulation software to both collect the appropriate data to create a model and to actually generate the base-case simulation model. These difficulties decrease the usefulness of simulation software and limit its application in areas in which it could be potentially useful. This research proposes and evaluates a data collection and analysis methodology that would allow for the programmatic generation of simulation models using production tracking data. It uses data collected from a GPS device that follows …

Reducing Drifts In Buckling Restrained Braced Framesthrough Elastic Stories, Jennifer Lorraine Craft

Theses and Dissertations

It is possible to reduce residual and maximum drifts in buildings by adding “elastic stories” that engage gravity columns in seismic response. An elastic story is a story wherein the buckling restrained brace frame (BRBF) size is increased to prevent yielding when an earthquake occurs. Buildings ranging from 4–16 stories were designed with various elastic story brace sizes and locations to determine the optimal combination to best reduce drifts. Gravity column stiffnesses were also varied in elastic story buildings to determine the effects on drifts. Computer models were used to analyze these buildings under a suite of earthquakes. Adding elastic …

Preemptive Placement And Routing For In-Field Fpga Repair, Joshua E. Jensen

Theses and Dissertations

With the growing density and shrinking feature size of modern semiconductors, it is increasingly difficult to manufacture defect free semiconductors that maintain acceptable levels of reliability for long periods of time. These systems are increasingly susceptible to wear-out by failing to meet their operational specifications for an extended period of time. The reconfigurability of FPGAs can be used to repair post-manufacturing faults by configuring the FPGA to avoid a damaged resource. This thesis presents a method for preemptively preparing to repair FPGA devices with wear-out faults by precomputing a set of repair circuits that, collectively, can repair a fault found …

Experimental Testing Of Shallow Embedded Connections Between Steel Columns And Concrete Footings, Nicholas Valgardson Barnwell

Theses and Dissertations

Shallow embedded column connections are widely used for columns resisting gravity loads in current design methods. These connections are usually considered “pinned” for structural analysis. In reality these connections fall in between a fixed and a pinned condition. Although methods exist to estimate the stiffness and strength of exposed columns or embedded columns under lateral loads, little research has been done to determine the strength of shallow embedded columns. An experimental study was carried out to investigate the strength of these connections. A total of 12 specimens with varying orientation, embedment depth, and column size were loaded laterally until failure …

An Investigation Of Friction Stir Welding Parameter Effects On Post Weld Mechanical Properties In 7075 Aa, Steven B. Dickson

Theses and Dissertations

The effects of weld temperature, travel speed, and backing plate thermal diffusivity on themechanical properties of a weld have been studied. A face centered cubic experiment of designwas completed in which the response variables were yield strength, minimum hardness in the HAZ, and charpy impact toughness. Three models were created from the data gathered usinga stepwise regression in order to see the effects of each parameter. For the yield strength andminimum hardness it was found that only travel speed and backing plate thermal diffusivities werestatistically significant to the properties. The charpy impact toughness saw that all three parameterswere statistically significant …

Temperature And Stress Effect Modeling In Fatigue Of H13 Tool Steel At Elevated Temperatures With Applications In Friction Stir Welding, Bradley Valiant Jones

Theses and Dissertations

Tooling reliability is critical to welding success in friction stir welding, but tooling fatigue is not well understood because it occurs in conditions that are often unique to friction stir welding. A fatigue study was conducted on a commonly used tooling material, H13 tool steel, using constant stress loading at temperatures between 300°C and 600°C, and the results are presented. A model is proposed accounting for temperature and stress effects on fatigue life, utilizing a two-region Arrhenius temperature model. A transition in temperature effect on fatigue life is identified. Implications of the temperature effect for friction stir welding suggest that …

Nonlinear Estimation And Control With Application To Upstream Processes, Reza Asgharzadeh Shishavan

Theses and Dissertations

Subsea development and production of hydrocarbons is challenging due to remote andharsh conditions. Recent technology development with high speed communication to subsea anddownhole equipment has created a new opportunity to both monitor and control abnormal or undesirableevents with a proactive and preventative approach rather than a reactive approach. Twospecific technology developments are high speed, long-distance fiber optic sensing for productionand completion systems and wired pipe for drilling communications. Both of these communicationsystems offer unprecedented high speed and accurate sensing of equipment and processes that aresusceptible to uncontrolled well situations, leaks, issues with flow assurance, structural integrity,and platform stability, as well …

Uav Navigation And Radar Odometry, Eric Blaine Quist

Theses and Dissertations

Prior to the wide deployment of robotic systems, they must be able to navigate autonomously. These systems cannot rely on good weather or daytime navigation and they must also be able to navigate in unknown environments. All of this must take place without human interaction. A majority of modern autonomous systems rely on GPS for position estimation. While GPS solutions are readily available, GPS is often lost and may even be jammed. To this end, a significant amount of research has focused on GPS-denied navigation. Many GPS-denied solutions rely on known environmental features for navigation. Others use vision sensors, which …

Heterogeneous Catalyst Deactivation And Regeneration: A Review, Morris D. Argyle, Calvin H. Bartholomew

Faculty Publications

Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key features and considerations for each of these deactivation types is reviewed in detail with reference to the latest literature reports in these areas. Two case studies on the deactivation mechanisms of catalysts used for cobalt Fischer-Tropsch and selective catalytic reduction are considered to provide additional depth in the topics of …

A Cloud-Based Modflow Service For Aquifer Management Decision Support, David Jones, Norm Jones, James Greer, Jim Nelson

Faculty Publications

A framework to publish simplified MODFLOW groundwater modeling capabilities to a web interface for use by water managers and stakeholders is presented. Numerical modeling simulations can assist aquifer management decisions, but the amount of time and professional expertise required to wield modern groundwater models often exceeds the resources of regulating agencies – even for simple modeling tasks that are repetitive in nature. The framework is capable of automating such modeling tasks, accepting user input, executing MODFLOW, and generating specialized results including maps and modeling reports. This framework was used to build a pilot system for an aquifer in central Utah, …

Experimental Measurements Of The Spectral Absorption Coefficient Of Pure Fused Silica Optical Fibers, Travis J. Moore, Matthew R. Jones

Faculty Publications

Knowledge of the spectral absorption coefficient of fused silica optical fibers is important in modeling heat transfer in the processes and applications in which these fibers are used. An experimental method used to measure the spectral absorption coefficient of optical fibers is presented. Radiative energy from a blackbody radiator set at different temperatures is directed through the optical fibers and into an FTIR spectrometer. Spectral instrument response functions are calculated for different fiber lengths. The ratios of the slopes of the instrument response functions for the different lengths of fibers are used to solve for the spectral absorption coefficient of …

A Review Of Open Source Software Solutions For Developing Water Resources Web Applications, Nathan R. Swain, Kilisimasi Latu, Scott D. Christensen, Norman L. Jones, E. James Nelson, Daniel P. Ames, Gustavious P. Williams

Faculty Publications

Water resources web applications or “web apps” are growing in popularity as a means to overcome many of the challenges associated with hydrologic simulations in decision-making. Water resources web apps fall outside of the capabilities of standard web development software, because of their spatial data components. These spatial data needs can be addressed using a combination of existing free and open source software (FOSS) for geographic information systems (FOSS4G) and FOSS for web development. However, the abundance of FOSS projects that are available can be overwhelming to new developers. In an effort to understand the web of FOSS features and …

Characterization Of Geometrically Necessary Dislocation Content With Ebsd-Based Continuum Dislocation Microscopy, Tim Ruggles

Theses and Dissertations

Modeling of plasticity is often hampered by the difficulty in accurately characterizing dislocationdensity on the microscale for real samples. It is particularly difficult to resolve measureddislocation content onto individual dislocation systems at the length scales most commonly of interestin plasticity studies. Traditionally, dislocation content is analyzed at the continuum levelusing the Nye tensor and the fundamental relation of continuum dislocation theory to interpret informationmeasured by diffraction techniques, typically EBSD or High Resolution EBSD. In thiswork the established Nye-Kroner method for resolving measured geometrically necessary dislocationcontent onto individual slip systems is assessed and extended. Two new methods are alsopresented to relieve …

Compressibility Measurement And Modeling To Optimize Flow Simulation Of Vacuum Infusion Processing For Composite Materials, Paul Hannibal

Theses and Dissertations

Out-of-autoclave manufacturing processes for composite materials are increasing in importance for aerospace and automotive industries. Vacuum Infusion processes are leading the push to move out of the autoclave. An understanding of the various process parameters associated with resin infusion is necessary to produce quality product. Variance in compaction, resin, and vacuum pressures are studied, concentrating on developing a compaction pressure profile as it relates to fiber volume fraction. The purpose of this research is twofold: (1) to show and quantify the existence of a resin pressure gradient in compression testing using rigid tooling, and (2) to use measured test data …

Non-Dimensional Approach For Static Balancing Of Rotational Flexures, Ezekiel G. Merriam, Larry L. Howell

Faculty Publications

This work presents a nondimensional method for statically balancing flexural hinges, including those with stiffness that varies with load. Using a set of non-dimensional parameters, it is shown that one can quickly design a balancing mechanism for an idealized hinge/torsion spring system. This method is then extended to load-dependent systems, and is demonstrated with the design of a balanced cross-axis-flexural pivot with stiffness that varies as a function of compressive preload. A physical prototype is built and tested to verify the design method. The prototype demonstrates an average stiffness reduction of 87% over an 80 degree deflection range. The method …

Energy Process Enabled By Cryogenic Carbon Capture, Mark Jensen

Theses and Dissertations

Global climate change concerns help shape current environmental regulations, which increasingly seek to reduce or capture CO2 emissions. Methods for capturing CO2 emissions from energy processes have been the focus of numerous studies to provide support for those seeking to reduce the environmental impact of their processes. This research has (1) simulated a baseline case of energy-storing cryogenic carbon capture for implementation on a 550 MWe coal fired power plant, (2) presented a novel cryogenic carbon capture process for removing CO2 from natural gas down to arbitrary levels, (3) presented a natural gas liquefaction process that has the ability to …

The Effects Of Multiple Probes On The Hybridization Of Target Dna On Surfaces, Ryan C. Welling, Thomas A. Knotts Iv

Faculty Publications

DNA microarrays have disruptive potential in many fields including genetics and medicine, but the technology has yet to find widespread clinical use due to poor reliability. Microarrays work on the principle of hybridization and can only be as dependable as this process is reliable. As such, a significant amount of theoretical research has been done to understand hybridization on surfaces on the molecular level. Previous simulations of a target strand with a single, surface-tethered probe molecule have yielded valuable insights, but such is an ideal system and little is known about the effects of multiple probes—a situation that more closely …

Development Of A Thickness Accommodation Technique For Origami-Inspired Design, Bryce Edmondson

Theses and Dissertations

Designers are constantly searching for new sourcing of inspiration for innovative design. Recently, origami has gained interest as one of these potential sources. Origami literally translated from Japanese means “paper folding” where “oru” means “to fold” and “kami” means “paper”. Since paper is insufficient to solve many engineering design problems, designers must turn to other materials. These materials will inevitably be thicker than paper and will often require different folding techniques and considerations. This thesis provides background information describing previous methods to accommodate thickness in origami-inspired design, presents a newly developed technique to address limitations of other methods, and explores …

Simulation Of The Swelling Of High-Volatile Bituminous Coal During Pyrolysis. Part 2: Influence Of The Maximum Particle Temperature, He Yang, Thomas H. Fletcher, Ming Dong

Faculty Publications

A model was established previously to predict the swelling ratio of high-volatile bituminous coal during pyrolysis based on the assumption that the structure of bubble distribution in the particle at the beginning of the plastic stage is a central bubble surrounded by many surrounding bubbles. The initial number and size of the bubbles when the particles become plastic are calculated by the pressure in the particle, and the chemical percolation devolatilization (CPD) model is used to describe pyrolysis. In this paper, to obtain accurate results at low pyrolysis temperatures, the previous model is improved and the following parts in the …

Stress-Limiting Test Structures For Rapid Low-Cost Strength And Stiffness Assessment, Andrew Katz, Craig P. Lusk, Nathan B. Crane

Faculty Publications

Purpose: Evaluate the use of a simple printed geometry to estimate mechanical properties (elastic modulus, yield strength) with inexpensive test equipment.

Design Methodology/Approach: Test geometry is presented that enables controlled strains with manual deformation and repeatable measurement of vibrational frequencies. This is tested with multiple FDM machines to assess measurement accuracy and repeatability. Printing orientation and some printing parameters are varied to assess the measurement sensitivity.

Findings: The test methods show good correlation with manufacturer material specifications in the X-Y plane and reported elastic strain limits. It is also sensitive to printing orientation and printing parameters.

Research Limitations/Implications: Further work …

Modeling Light Gas And Tar Yields From Pyrolysis Of Green River Oil Shale Demineralized Kerogen Using The Chemical Percolation Devolatilization Model, Daniel Barfuss, Ronald J. Pugmire, Thomas H. Fletcher

Faculty Publications

Recent detailed chemical structure analyses of three demineralized kerogens from Green River oil shale samples were used to generate input parameters for the chemical percolation devolatilization (CPD) model. This model uses a lattice network to describe pyrolysis of solid hydrocarbons, such as coal and biomass. It was necessary to modify the formulation of the CPD model to account for the long aliphatic carbon chains found in oil shale, because gases formed from these long chains condense at room temperature and are counted as tar. It was initially assumed that 20% of the aliphatic material was released as light gas during …

Steam Gasification Rates Of Three Bituminous Coal Chars In An Entrained-Flow Reactor At Pressurized Conditions, Aaron D. Lewis, Troy M. Holland, Nathaniel R. Marchant, Emmett G. Fletcher, Danley J. Henley, Eric G. Fuller, Thomas H. Fletcher

Faculty Publications

Three bituminous coal chars (Illinois #6, Utah Skyline, and Pittsburgh #8) were gasified separately at total pressures of 10 and 15 atm in an entrained-flow reactor using gas temperatures up to 1830 K and particle residence times gasification, although select experiments were performed at conditions where significant mass release was due to gasification by both H2O and CO2. The measured coal data were fit to three char gasification models including a simple first-order global model, as well as the CCKN and CCK models that stem from the CBK model. The optimal kinetic parameters for each of the three models are …

Fuel Element Combustion Properties For Live Wildland Utah Shrubs, Thomas H. Fletcher, Chen Shen

Faculty Publications

Current field models for wildfire prediction are mostly based on dry or low-moisture fuel combustion research. To better study the live fuel combustion behavior, a laminar flow flat-flame burner was used to provide a convection heating source to ignite an individual live fuel sample. In this research project, four Utah species were studied: Gambel oak (Quercus gambelii), canyon maple (Acer grandidentatum), big sagebrush (Artemisia tridentata), and Utah juniper (Juniperus osteosperma). Leaf geometrical parameters measured included individual leaf total mass, thickness, leaf width, leaf length, and moisture content. Time-stamped images of combustion behavior along with time-dependent mass data were recorded via …

Thick Rigidly Foldable Structures Realized By An Offset Panel Technique, Bryce Edmondson, Robert J. Lang, Michael R. Morgan, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Rigid-panel origami is often mathematically modeled with idealized zero-thickness panels. When paper is used to realize an origami design, the zero-thickness models are a good approximation. However, many origami-inspired designs require the use of thicker materials that likely will not behave as the zero-thickness kinematic models predict.

The offset panel technique defined previously by the authors [Edmondson et al. 14] maintains the kinematics of a zero-thickness origami source model over its full range of motion. The offset panel technique accommodates uniform and varying panel thickness as well as offset panels or gaps between panels. The preserved kinematic behavior allows designers …

Rigidly Foldable Origami Twists, Thomas A. Evans, Robert J. Lang, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Rigid foldability is an important characteristic of origami structures that becomes significant with non-paper materials. A rigidly foldable origami tessellation is one where the sectors remain rigid and all deflection occurs at the crease lines. Many rigidly foldable patterns have only one degree of freedom, making them potentially useful for deployable structures. Methods have been developed to construct rigidly foldable origami tessellations using materials with finite thickness based on zero-thickness rigidly foldable patterns. [Tachi 11].

Origami methods have been considered for application in deployable structures such as solar panels [Miura 85] [Zirbel et al. 13] and sterile shrouds [Francis et …

Development And Validation Of A New Blade Element Momentum Skewed-Wake Model Within Aerodyn, Andrew Ning, Greg Hayman, Rick Damiani, Jason Jonkman

Faculty Publications

Blade element momentum methods, though conceptually simple, are highly useful for analyzing wind turbines aerodynamics and are widely used in many design and analysis applications. A new version of AeroDyn is being developed to take advantage of new robust solution methodologies, conform to a new modularization framework for National Renewable Energy Laboratory’s FAST, utilize advanced skewed-wake analysis methods, fix limitations with previous implementations, and to enable modeling of highly flexible and nonstraight blades. This paper reviews blade element momentum theory and several of the options available for analyzing skewed inflow. AeroDyn implementation details are described for the benefit of users …

The Application And Accuracy Of Structure From Motion Computer Vision Models With Full-Scale Geotechnical Field Tests, L. Palmer, Kevin W. Franke, R. Abraham Martin, B. E. Sines, Kyle M. Rollins, John Hedengren

Faculty Publications

Structure from motion (SfM) computer vision is a relatively new technology that allows engineers to reconstruct a three-dimensional (3D) model of a given scene using twodimensional digital photographs captured from a single, moving camera. SfM computer vision provides an economic and user-friendly alternative to other 3D scene-capture and modeling tools such as light distance and ranging (LiDAR). Although the resolution and accuracy of laser-based modeling methods are generally superior to vision-based modeling methods, the economic advantages associated with the latter may make it a useful and practical alternative for many geotechnical engineering applications. Although other engineering disciplines have investigated the …

Electrowetting Force And Velocity Dependence On Fluid Surface Energy, Qi Ni, Daniel E. Capecci, Nathan B. Crane

Faculty Publications

Electrowetting on Dielectric is a phenomenon in which the shape and apparent contact angle of a droplet changes when an electric field is applied across the droplet interface. If the field is asymmetric with respect to the droplet, then a net force can be applied to the droplet. In this work, we have measured the electrowetting force by confining the droplet shape beneath a glass plate and measuring the force on the plate. The force was measured as a function of voltage for a range of fluids with different surface energy. Measured forces show excellent agreement with predictions based on …