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Effects Of Various Mobility Aids On Lower-Extremity Muscle Activity, Michael Ryan Sanders
Effects Of Various Mobility Aids On Lower-Extremity Muscle Activity, Michael Ryan Sanders
Theses and Dissertations
Millions of people each year spend some portion of their time using mobility aids to facilitate periods of non-weight bearing ambulation. The use of these devices changes the loading conditions of the lower extremities, which may result in skeletal muscle adaptations. The purpose of this work was to evaluate the effects of 3 types of mobility aids on lower-extremity muscle activity. Evaluation was based on 1) measured muscle activation signals using electromyography (EMG), and 2) measured joint kinematics and ground reaction forces, which were used to predict muscle forces. 16 healthy subjects (7 female, 9 male), ages 18-27 participated in …
Elucidating The Mechanisms Of Rate-Dependent Deformation At Ambient Temperatures In A Model Metallic Glass, Matthew Bradley Harris
Elucidating The Mechanisms Of Rate-Dependent Deformation At Ambient Temperatures In A Model Metallic Glass, Matthew Bradley Harris
Theses and Dissertations
In this work, the Shear Transformation Zone (STZ) dynamics model is adapted to capture the transitions between different regimes of flow serration in the deformation map of metallic glass. This was accomplished by scaling the STZ volume with a log-linear fit to the strain rate, and also adjusting the activation energy of an STZ with a log-linear fit to maintain constant yield strength at differing strain rates. Twelve simulations are run at each of six different strain rates ranging from 10-5 to 100 s-1, and statistics are collected on simulation behavior and shear band nucleation and …
Springback Force Considerations In Compliant Haptic Interfaces, Dallin R. Swiss
Springback Force Considerations In Compliant Haptic Interfaces, Dallin R. Swiss
Theses and Dissertations
This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an …
Springback Force Considerations In Compliant Haptic Interfaces, Dallin R. Swiss
Springback Force Considerations In Compliant Haptic Interfaces, Dallin R. Swiss
Theses and Dissertations
This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an …
Aerodynamic Improvement Of The Byu Supermileage Vehicle, Sayan Dobronsky
Aerodynamic Improvement Of The Byu Supermileage Vehicle, Sayan Dobronsky
Theses and Dissertations
The purpose of this thesis work was to design a new shape for the BYU Supermileage vehicle in order to improve its fuel efficiency. Computational Fluid Dynamics (CFD) was used to obtain the coefficient of drag (CD) and drag area of the current baseline vehicle at a Reynolds number of 1.6x10^6 and 8.7x10^5. Then a new shape was developed using mesh morphing software. The new shape was imported into the CFD program and the drag figures and airflow plots from the modified design were compared with the baseline vehicle. Scale models of the vehicles were also printed using a 3D …
Design And Manufacture Of Mesoscale Robot-Actuated Surgical Instruments, Clayton L. Grames
Design And Manufacture Of Mesoscale Robot-Actuated Surgical Instruments, Clayton L. Grames
Theses and Dissertations
Minimally Invasive Surgery (MIS) is a growing field including both laparoscopic androbotic operations. Surgeons and engineers are making continual efforts to reduce the negative effects of procedures on patients. Reducing the size of the surgical instruments is one effective method pursued in this effort. When the instruments approach 3 mm in diameter, they reach a threshold where the entry incisions can be small enough that no scar is left on the patient. Laparoscopic instruments on this scale exist but typically lack wrist articulation and only have 1 degree of freedom (DoF). Alternatively, robotic surgical instruments can achieve high levels of …
Design And Validation Of A Complex Loading Whole Spinal Segment Bioreactor, Amanda Marie Beatty
Design And Validation Of A Complex Loading Whole Spinal Segment Bioreactor, Amanda Marie Beatty
Theses and Dissertations
Intervertebral disc (IVD) degeneration is a prevalent health problem that is highly linked to back pain. To understand the disease and tissue response to therapies, ex-vivo whole IVD organ culture systems have recently been introduced. The goal of this study was to develop and validate a whole spinal segment culturing system that loads the disc in complex loading similar to the in-vivo condition, while preserving the adjacent endplates and vertebral bodies. The complex loading applied to the spinal segment was achieved with three pneumatic cylinders. The pneumatic cylinders were rigidly attached to two triangular alumni plates at each corner, comprising …
Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster
Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster
Theses and Dissertations
The client-server architecture of STAR-CCM+ allows multiple users to collaborate on a simulation set-up. The effectiveness of collaboration with this architecture is tested and evaluated on five models. The testing of these models is a start to finish set-up of an entire simulation excluding computational time for generating mesh and solving the solution. The different models have distinct differences which test every operation that would be used in a general CFD simulation. These tests focus on reducing the time spent preparing the geometry to be meshed, including setting up for a conformal mesh between multiple regions in conjugate heat transfer …
An Approach For Designing Origami-Adapted Products With Aerospace Mechanism Examples, Jessica Morgan
An Approach For Designing Origami-Adapted Products With Aerospace Mechanism Examples, Jessica Morgan
Theses and Dissertations
The objective of this research is to develop a design process for origami-adapted products and demonstrate it using aerospace mechanism examples. Origami-adapted design is a type of origami-based design. Origami-based design ranges from abstract to concrete applications of origami to design and includes: origami-inspired design, origami-adapted design, and origami-applied design. Origami-adapted design adapts origami fold patterns into products while preserving functionality. Some of the desirable attributes of origami that are sought after in design include: 1) reduced number of parts, 2) stowability, 3) deployability, 4) transportability, 5) manufacturability from a flat sheet of material, 6) ease of miniaturization, 7) a …
Neutral Parametric Canonical Form For 2d And 3d Wireframe Cad Geometry, Robert Steven Freeman
Neutral Parametric Canonical Form For 2d And 3d Wireframe Cad Geometry, Robert Steven Freeman
Theses and Dissertations
The challenge of interoperability is to retain model integrity when different software applications exchange and interpret model data. Transferring CAD data between heterogeneous CAD systems is a challenge because of differences in feature representation. A study by the National Institute for Standards and Technology (NIST) performed in 1999 made a conservative estimate that inadequate interoperability in the automotive industry costs them $1 billion per year. One critical part of eliminating the high costs due to poor interoperability is a neutral format between heterogeneous CAD systems. An effective neutral CAD format should include a current-state data store, be associative, include the …
Improving The Suction Performance And Stability Of An Inducer With An Integrated Inlet Cover Bleed System Known As A Stability Control Device, Ryan K. Lundgreen
Improving The Suction Performance And Stability Of An Inducer With An Integrated Inlet Cover Bleed System Known As A Stability Control Device, Ryan K. Lundgreen
Theses and Dissertations
The performance of an inducer with the integration of an inlet cover bleed system known as a stability control device (SCD) is investigated using computational fluid dynamics. Inducers are the first stage of high suction performance pumps and are designed to operate under cavitating conditions. Improvements in design have allowed inducers to operate stably with low inlet head conditions, however, cavitation instabilities ultimately lead to pump failure. It has been shown that inducers that employ an SCD fully suppress cavitation instabilities.The performance of an inducer is explored at both on- and off-design flow coefficients, where the flow coefficient is a …
Jet And Droplet Impingement On Superhydrophobic Surfaces, Jonathan Glenn Stoddard
Jet And Droplet Impingement On Superhydrophobic Surfaces, Jonathan Glenn Stoddard
Theses and Dissertations
The effect of superhydrophobicity on liquid water impingement on a flat horizontal surface was explored. The surfaces combined a hydrophobic surface chemistry with a patterned microstucture in order to produce high contact angles with water. Three sets of experiments were performed, one for jet impingement and two for droplet impingement, which advance previous work in characterizing the interaction of water and superhydrophobic surfaces.Jet impingement experiments were performed to characterize a transitional regime between an unsubmerged and a completely submerged superhydrophobic surface by varying an imposed downstream depth. For low downstream depths, the surface remained unsubmerged and displayed only break up …
Geometry And Material Properties Of Vocal Fold Models, Kimberly Ann Stevens
Geometry And Material Properties Of Vocal Fold Models, Kimberly Ann Stevens
Theses and Dissertations
Voiced communication plays a fundamental role in society. Voice research seeks to improve understanding of the fundamental physics governing voice production, with the eventual goal of improving methods to diagnose and treat voice disorders. For this thesis, three different aspects of voice production research were studied. First, porcine vocal fold medial surface geometry was determined, and the three-dimensional geometric distortion induced by freezing the larynx, especially in the region of the vocal folds, was quantified. It was found that porcine vocal folds are qualitatively geometrically similar to canine and human vocal folds, as well as commonly used models, and that …
Composition Based Modaling Of Silicone Nano-Composite Strain Gauges, Daniel Alexander Baradoy
Composition Based Modaling Of Silicone Nano-Composite Strain Gauges, Daniel Alexander Baradoy
Theses and Dissertations
In this work a review of the technology surrounding high deflection strain sensing with an emphasis on that of a recently developed nickel nano-composite strain sensor is presented. A new base silicone material was identified for the nickel nano-composite strain sensor that improves its mechanical stiffness and conductive properties. A previously identified cyclic creep concern was mitigated through preconditioning and the use of adhered backing materials. Through a block design experiment the strain/resistance curves for the strain sensors were characterized over a wide range of nano-filler material compositions. An analytical model was developed based on observation that the resistance of …
Temperature Measurement Using Infrared Spectral Band Emissions From H2o, Daniel Jared Ellis
Temperature Measurement Using Infrared Spectral Band Emissions From H2o, Daniel Jared Ellis
Theses and Dissertations
Currently there is no known method for accurately measuring the temperature of the gas phase of combustion products within a solid fuel flame. The industry standard is a suction pyrometer and thermocouple which is intrusive, both spatially and temporally averaging, and difficult to use. In this work a new method utilizing the spectral emission from water vapor is investigated through modeling and experimental measurements. This method was demonstrated along a 0.75m line of sight, averaged over 1 minute in the products of a natural gas flame but has the potential to produce a spatial resolution on the order of 5 …
Transport Enhancement Of Rate-Limited Chemical Reactions Via Pt-Decorated, Carbon Nanotube Microarray Membranes, Kevin M. Marr
Transport Enhancement Of Rate-Limited Chemical Reactions Via Pt-Decorated, Carbon Nanotube Microarray Membranes, Kevin M. Marr
Theses and Dissertations
Rate limited chemical reactions can be enhanced by improving the mass transport of the suspended analyte to the catalytic (or electrocatalytic) surface. While many attempts have been made to enhance this mass transport, these approaches are limited to utilizing only two enhancement methods – increasing available catalytic surface area, and increasing the flow of analyte in solution. Flow through high aspect ratio microstructures, however, would provide additional mass transport enhancement via boundary layer confinement. Platinum functionalized carbon nanotube microarray membranes (Pt-CNT-MMs) offer enhanced mass transport via all three methods, and were fabricated for demonstration in a H2O2 sample system, for …
A Study Of Carbon Infiltrated Carbon Nanotubes Fabricated On Convex Cylindrical Substrates For The Creation Of A Coronary Stent, Warren Beecroft Robison
A Study Of Carbon Infiltrated Carbon Nanotubes Fabricated On Convex Cylindrical Substrates For The Creation Of A Coronary Stent, Warren Beecroft Robison
Theses and Dissertations
This research explores the minimizing of cracks in the fabrication of carbon-infiltrated carbon nanotube (CI-CNT) forests on cylindrical rods for the purposes of creating a CI-CNT coronary stent. It is a continuation of the work begun by Jones [1] and Skousen [2] whose work included the creation of a feasible CI-CNT coronary stent on a planar surface. The current research was performed in two parts: 1) growth on the whole circumference of the rod for ~20mm in length and 2) growth in lines and patterns. Experiments were done on either a 309 or 304 stainless steel rod ~3mm in diameter.The …
Integrating Synchronous Collaborative Applications With Product Lifecycle Management Workflows, Jordan Lowell Johnson
Integrating Synchronous Collaborative Applications With Product Lifecycle Management Workflows, Jordan Lowell Johnson
Theses and Dissertations
Product Lifecycle Management (PLM) systems are used by thousands of engineering companies world wide. Improving these systems will have a drastic and global effect. One possible improvement is to integrate synchronous collaborative applications with PLM systems. These applications allow multiple people to work on a single digital object simultaneously. They have already been shown to reduce the time a task requires. Using these applications to complete a project will reduce the project time. However, simply including synchronous collaborative applications within a PLM system ignores powerful benefits that could provide further time-saving benefits. The integration must allow improved awareness at the …
Investigation Of Parameters Affecting The Nanoinjection Of Hela 229 Cancer Cells, Tyler E. Lewis
Investigation Of Parameters Affecting The Nanoinjection Of Hela 229 Cancer Cells, Tyler E. Lewis
Theses and Dissertations
The ability to deliver sequences of DNA and other molecular loads across the membrane of a cell and into its nucleus is an area of interest in the medical community. One of its many applications is that of gene therapy. In contrast to other forms of treatment, gene therapy seeks to treat diseases at the cellular level. The success of these treatments depends on the technologies for cell transfection that are available. Physical methods are sometimes able to overcome poor efficiencies of chemical methods and the safety concerns of viral methods, but are usually impractical due to the limited number …
Using The Offset Panel Technique To Develop Innovative Origami-Based Applications, Michael Robert Morgan
Using The Offset Panel Technique To Develop Innovative Origami-Based Applications, Michael Robert Morgan
Theses and Dissertations
Origami, the art of folding paper, was once only an art form. In recent years, it has collided with the world of engineering and is acting as a source of inspiration for solutions to various engineering problems. Paper, the typical material used in the art form, is thin and works well for origami, but is not often suitable for use in engineering. Researchers have developed a handful of methods for accommodating thick/rigid materials in origami design. Most of these preserve only the kinematics of the model or its range of motion. Not only does the offset panel technique (OPT) preserve …
Temperature Control In Friction Stir Welding Using Model Predictive Control, Brandon Scott Taysom
Temperature Control In Friction Stir Welding Using Model Predictive Control, Brandon Scott Taysom
Theses and Dissertations
Temperature is a very important process parameter in Friction Stir Welding (FSW), but until lately active control of temperature has not been practiced. Recently, temperature control via a PID controller has proven to be effective. Model Predictive Control (MPC) is a control method that holds promise, but has not been attempted in FSW before. Two different model forms are developed for MPC and are evaluated. The first is a simple first-order plus dead time (FOPDT) model. The second is the Hybrid Heat Source model and is more complex; it combines the heat source method and a 1D discretized thermal model …
On The Free Surface Skipping Characteristics Of Highly Deformable Elastic Spheres, Randy C. Hurd
On The Free Surface Skipping Characteristics Of Highly Deformable Elastic Spheres, Randy C. Hurd
Theses and Dissertations
When a highly deformable elastic sphere impacts a water surface at an oblique angle it can skip several times in a manner similar to a skipping stone. However, this sphere seems to skip more readily and with more ease than a traditional skipping stone. This thesis examines the improved skipping characteristics of highly deformable elastic spheres made from cured silicone rubber. The effect of impact velocity, impact angle, sphere diamter and material shear modulus on ricochet trajectory is experimentally examined using high speed photography and image processing techniques. Experimental evaluation shows that deformation is the primary contributor to an increased …
A Collaborative Conceptual Aircraft Design Environment For The Design Of Small-Scale Uavs In A Multi-University Setting, Joseph Samuel Becar
A Collaborative Conceptual Aircraft Design Environment For The Design Of Small-Scale Uavs In A Multi-University Setting, Joseph Samuel Becar
Theses and Dissertations
In today's competitive global market, there is an ever-increasing demand for highly skilled engineers equipped to perform in teams dispersed over several time-zones by geography. Aerospace Partners for the Advancement of Collaborative Engineering (AerosPACE) is a senior design capstone program co-developed by academia and industry to help students develop the necessary skills to excel in the aerospace industry by challenging them to design, build, and fly an unique unmanned aerial vehicle (UAV). Students with little to no experience designing UAVs are put together in teams with their peers from geographically dispersed universities. This presents a significant challenge for the students …
An Automated Method For Hot-To-Cold Geometry Mapping, Brandon Levi Doolin
An Automated Method For Hot-To-Cold Geometry Mapping, Brandon Levi Doolin
Theses and Dissertations
An Automated Method for Hot-to-Cold Geometry Mapping.
Active Control Of The Human Voice From A Sphere, Monty J. Anderson
Active Control Of The Human Voice From A Sphere, Monty J. Anderson
Theses and Dissertations
This work investigates the application of active noise control (ANC) to speech. ANC has had success reducing tonal noise. In this work, that success was extended to noise that is not completely tonal but has some tonal elements such as speech. Limitations such as causality were established on the active control of human speech. An optimal configuration for control actuators was developed for a sphere using a genetic algorithm. The optimal error sensor location was found from exploring the nulls associated with the magnitude of the radiated pressure with reference to the primary pressure field. Both numerically predicted and experimentally …
A Multi-Objective Optimization Method For Maximizing The Value Of System Evolvability Under Uncertainty, Jason Daniel Watson
A Multi-Objective Optimization Method For Maximizing The Value Of System Evolvability Under Uncertainty, Jason Daniel Watson
Theses and Dissertations
System evolvability is vital to the longevity of large-scale complex engineered systems. The need for evolvability in complex systems is a result of their long service lives, rapid advances to their integrated technologies, unforeseen operating conditions, and emerging system requirements. In recent years, quantifiable metrics have been introduced for measuring the evolvability of complex systems based on the amount of excess capability in the system. These metrics have opened opportunities for optimization of systems with evolvability as an objective. However, there are several aspects of such an optimization that require further consideration. For example, there is a trade-off between the …
Concurrent Engineering Through Parallelization Of The Design-Analysis Process, Eric Joseph Wardell
Concurrent Engineering Through Parallelization Of The Design-Analysis Process, Eric Joseph Wardell
Theses and Dissertations
The disconnect between the way CAD and analysis applications handle model geometry has long been a hindrance to engineering design. Current industry practices often utilize outdated forms of geometry transfer between these different engineering software applications such as neutral file formats and direct translations. Not only to these current practices slow the engineering design process but they also hinder the integration of design and analysis programs.This thesis proposes a new, multi-user, integrated design-analysis architecture which allows auxiliary functions such as analysis and computer-aided manufacturing to be better connected with the computer-aided design. It is hypothesized that this new architecture will …
Burnout, No, And Flame Characterization From An Oxygen-Enriched Biomass Flame, Steven Andrew Owen
Burnout, No, And Flame Characterization From An Oxygen-Enriched Biomass Flame, Steven Andrew Owen
Theses and Dissertations
Concern for the environment and a need for more efficient energy generation have sparked a growing interest throughout the world in renewable fuels. In order to reduce emissions that negatively contribute to global warming, especially CO2, enormous efforts are being invested in technologies to reduce our impact on the environment. Biomass is an option that is considered CO2 friendly due to the consumption of CO2 upon growth. Co-firing biomass with coal offers economic advantages because of reduced capital costs as well as other positive impacts, such as NOx and SOx emission reductions. However, due to the large average particle size …
An Investigation Of Off-Design Operation In High Suction Performance Inducers, Ryan Collins Cluff
An Investigation Of Off-Design Operation In High Suction Performance Inducers, Ryan Collins Cluff
Theses and Dissertations
Three-dimensional two-phase unsteady CFD simulations were run on three and four-blade inducers for the purpose of analyzing differences in cavitation stability at design and off-design flow rates. At design flow rates, there were very small differences between the breakdown curves for the three and four-bladed inducers. However, at lower cavitation numbers, the three-bladed inducer exhibited up to three times the rotor forces than the four-bladed inducer. When moving to off-design flow rates, both inducers experienced multiple modes of cavitation instabilities including rotating cavitation, alternate-blade cavitation, and cavitation surge. The four-bladed inducer began experiencing the formation of these modes of instability …
Ligament Model Fidelity In Finite Element Analysis Of The Human Lumbar Spine, Mitchell Scott Hortin
Ligament Model Fidelity In Finite Element Analysis Of The Human Lumbar Spine, Mitchell Scott Hortin
Theses and Dissertations
The purpose of this project is to quantify the effects of increasing spinal ligament fidelity on the mechanics of the human lumbar spine using finite element analysis (FEA). In support of this goal, a material characterization study was completed to provide anisotropic, nonlinear material parameters for the human anterior longitudinal ligament. (ALL). Cadaveric samples of the human ALL were tested using a punch test technique. Multi- axial force-deformation data were gathered and fit to a commonly used transversely isotropic material model using an FEA system identification routine. The resulting material parameters produced a curve that correlated well with the experimental …