Engineering Commons^™

Prediction Of Fluid Dielectric Constants, Jiangping Liu

Theses and Dissertations

The dielectric constant or relative static permittivity of a material represents the capacitance of the material relative to a vacuum and is important in many industrial applications. Nevertheless, accurate experimental values are often unavailable and current prediction methods lack accuracy and are often unreliable. A new QSPR (quantitative structure-property relation) correlation of dielectric constant for pure organic chemicals is developed and tested. The average absolute percent error is expected to be less than 3% when applied to hydrocarbons and non-polar compounds and less than 18% when applied to polar compounds with dielectric constant values ranging from 1.0 to 50.0. A …

Mechanical Characterization Of The Interspinous Ligament Using Anisotropic Small Punch Testing, Rachel Jane Bradshaw

Theses and Dissertations

Objective: The objective of this work was to characterize the nonlinear anisotropic material constitutive response of the interspinous ligament (ISL).

Methods: Cadaveric test samples of the interspinous ligament were tested using the anisotropic small punch test. The measured force-displacement response served as experimental input into a system identification optimization routine to determine the constitutive material parameters that replicated the measured material response.

Results: The constitutive behavior of the ISL is notably different from that reported for knee, shoulder, and hip ligaments. Specifically, the high collagen fiber content and unique collagen architecture provided a stiffer material response. The results from the …

Friction Bit Joining Of 5754 Aluminum To Dp980 Ultra-High Strength Steel: A Feasibility Study, Britney Weickum

Theses and Dissertations

In this study, the dissimilar metals 5754 aluminum and DP980 ultra-high strength steel were joined using the friction bit joining (FBJ) process. The friction bits were made using one of three steels: 4140, 4340, or H13. Experiments were performed in lap shear, T-peel, and cross tension configurations, with the 0.070" thick 5754 aluminum alloy as the top layer through which the friction bit cut, and the 0.065" thick DP980 as the bottom layer to which the friction bit welded. All experiments were performed using a computer controlled welding machine that was purpose-built and provided by MegaStir Technologies. Through a series …

Characterization Of The Mechanical Response Of The Lumbar Spine, Shannon Alisa Zirbel

Theses and Dissertations

The primary objective of this research is to associate lumbar segmental mechanical response with intervertebral disc degeneration under physiologic testing conditions. Because no mathematical model exists for lumbar spine segmental rotations, a portion of this thesis evaluates potential methods for curve fitting the torque-rotation curves. The Dual Inflection Point (DIP) Boltzmann equation was developed during the course of this research and is presented here as a method for fitting spinal motion data wherein a physical meaning can be assigned to each of the model coefficients. This model can tell us more about the effects of degeneration, testing conditions, and other …

Fpga Communication Framework For Communication, Debugging, Testing, And Rapid Prototyping, Peter Andrew Lieber

Theses and Dissertations

FPGA-CF is an open-source, portable, extensible communications framework that consists of a small hardware core (less than 600 slices) and a software library/API (Java and C++). It enables a host PC to transmit data at 120 Mb/s to Xilinx-based FPGA boards via Ethernet using standard inter-networking protocols (UDP/IP). A custom lightweight connection-oriented protocol guarantees reliability. The hardware core is directly connected to the Xilinx internal configuration port (ICAP) and supports all ICAP functionality. The core also provides an extensible user-channel interface and provides up to 15, 8-bit user-data channels that can be connected to user circuitry (configurable by the user). …

Gis-Based Data Model And Tools For Creating And Managing Two-Dimensional Cross Sections, Timothy L. Whiteaker, Norm Jones, Gil Strassberg, Alan Lemon, Doug Gallup

Faculty Publications

While modern Geographic Information Systems (GIS) software is robust in handling maps and data in plan view, the software generally falls short when representing features in section view. Further complicating the issue is the fact that geologic cross sections are often drawn by connecting a series of wells together that do not fall along a single straight line. In this case, the x-axis of the cross section represents the distance along the set of individual lines connecting the series of wells, effectively “flattening out” the cross section along this path to create a view of the subsurface with which …

Integration Of Micropore And Nanopore Features With Optofluidic Waveguides For Single Particle Sensing, Matthew R. Holmes

Theses and Dissertations

This dissertation outlines the research and development of ground-breaking nanometer sized openings (nanopores) integrated with an on-chip optofluidic platform. This platform represents a significant advancement for single nanoparticle sensing. In this work specifically, the integrated optofluidic platform has been used to electrically and optically filter and detect single nanoparticles using ionic current blockade and fluorescence experiments. The correlation of electrical and optical signal has provided the highest sensitivity single nanoparticle measurements ever taken with integrated optofluidic platforms. The particular optofluidic platform used for this work is an antiresonant reflecting optical waveguide (ARROW). ARROW hollow and solid core waveguides are interference …

Devices And Methods For Electro-Physical Transport Of Dna Across Cell Membranes, Quentin Theodore Aten

Theses and Dissertations

A novel method for charged macromolecule delivery, called nanoinjection, has been developed at Brigham Young University. Nanoinjection combines micro-fabrication technology, mechanism design, and nano-scale electrical phenomenon to transport exogenous DNA across cell membranes on a nano-featured lance. DNA is electrically accumulated on the lance, precision movements of microelectromechanical systems (MEMS) physically insert the lance into cell, and DNA is electrically released from the lance into the cell. Penetration into the cell is achieved through a two-phase, self-reconfiguring metamorphic mechanism. The surface-micromachined, metamorphic nanoinjector mechanism elevates the lance above the fabrication substrate, then translates in-plane at a constant height as the …

A Wideband Precision Quadrature Phase Shifter, Steve T. Noall

Theses and Dissertations

A new circuit is proposed that uses an RC-CR filter in a feedback configuration to achieve a wideband precision quadrature phase shift with constant amplitude response. Such a circuit can be used to perform image rejection in a low IF receiver using the Hartley method. Simulation results show that the circuit can achieve an average image rejection ratio of 50 dB over a 16 MHz bandwidth. The feedback loop enables the circuit to maintain high accuracy over process and temperature.

Magnetic Field Sensing With Slab Coupled Optical Fiber Sensors, Bryson J. Shreeve

Theses and Dissertations

This thesis reports an in-fiber magnetic field sensor that is able to detect magnetic fields as low as 2 A/m at a spatial resolution of 1 mm. The small sensor consists of a magneto-optic slab waveguide, bismuth-doped rare earth iron garnet (Bi-RIG) that is coupled to an optical fiber. By coupling light from the fiber to the slab waveguide, it becomes an in-fiber magnetic field sensor. This is due to the Magneto-Optic Kerr effect; a change in refractive index is proportional to the applied magnetic field. When an AC field is applied, an AC component in the output power can …

Developing And Assessing Stem Curriculum With The Intent Of Promoting Technological Literacy, Scott Bartholomew, Geoff Wright, Ron Terry

Faculty Publications

Developing and Assessing STEM Curriculum with the Intent of Promoting Technological Literacy Technological literacy is a key component of President Barack Obama’s $260 Million STEM educational initiative (Office of the Press Secretary, 2009). Central to his plan is STEM teacher training and curriculum development. Both of these issues were addressed and are currently being measured by the research outlined in this paper. Spring2010 a collection of technology and engineering education graduate students developed with mentoring from two technology and engineering education professors 20 lesson unit and lesson plans promoting technological literacy. The lesson plans are currently being used and assessed …

An Evaluation Of Constitutive Laws And Their Ability To Predict Flow Stress Over Large Variations In Temperature, Strain, And Strain Rate Characteristic Of Friction Stir Welding, Katherine Lynn Kuykendall

Theses and Dissertations

Constitutive laws commonly used to model friction stir welding have been evaluated, both qualitatively and quantitatively, and a new application of a constitutive law which can be extended to materials commonly used in FSW is presented. Existing constitutive laws have been classified as path-dependent or path-independent. Path-independent laws have been further classified according to the physical phenomena they capture: strain hardening, strain rate hardening, and/or thermal softening. Path-dependent laws can track gradients in temperature and strain rate characteristic to friction stir welding; however, path-independent laws cannot. None of the path-independent constitutive laws evaluated has been validated over the full range …

Numerical Analysis On The Effects Of Blade Loading On Vortex Shedding And Boundary Layer Behavior In A Transonic Axial Compressor, Kenneth Phillip Clark

Theses and Dissertations

Multiple high-fidelity, time-accurate computational fluid dynamics simulations were performed to investigate the effects of upstream stator loading and rotor shock strength on vortex shedding characteristics in a single stage transonic compressor. Various configurations of a transonic axial compressor stage, including three stator/rotor axial spacings of close, mid, and far in conjunction with three stator loadings of decreased, nominal, and increased were simulated in order to understand the flow physics of transonic blade-row interactions. Low-speed compressors typically have reduced stator/rotor axial spacing in order to decrease engine weight, and also because there is an increase in efficiency with reduced axial spacing. …

Failing Drop Co2 Deposition (Desublimation) Heat Exchanger For The Cryogenic Carbon Capture Process, David William James

Theses and Dissertations

Cryogenic carbon capture removes CO2 and other pollutants from flue and waste stream gases produced from the combustion of fossil fuels such as coal, natural gas, and oil and the production of cement. A transient, 1-dimensional numerical model was developed to study the temperature profile within a counter-current surface CO2 desublimation-falling liquid or solid heat exchanger. Effects of desublimation heat and mass transfer as well as convective and conductive heat transfer relationships were taken into account. Experiments show that CO2 can be captured on a falling spherical particle when appropriate column operating conditions are met.

Experimental Characterization Of Baffle Plate Influence On Turbulent And Cavitation Induced Vibrations In Pipe Flow, Gavin J. Holt

Theses and Dissertations

Turbulent and cavitation induced pipe vibration is a large problem in industry often resulting in pipe failures. This thesis provides an experimental investigation on turbulent flow and cavitation induced pipe vibration caused by sharp edged baffle plates. Due to large pressure losses across a baffle plate, cavitation can result. Cavitation can be destructive to pipe flow in the form of induced pipe wall vibration and cavitation inception. Incipient and critical cavitation numbers are design points that are often used in designing baffle plate type geometries. This investigation presents how these design limits vary with the influencing parameters by exploring a …

Multi-Year Arctic Sea Ice Classification Using Quikscat, Aaron M. Swan

Theses and Dissertations

Long term trends in Arctic sea ice are of particular interest with regard to global temperature, climate change, and industry. This thesis uses microwave scatterometer data from QuikSCAT and radiometer data to analyze intra- and interannual trends in first-year and multi-year Arctic sea ice. It develops a sea ice type classification method. The backscatter of first-year and multi-year sea ice are clearly identifiable and are observed to vary seasonally. Using an average of the annual backscatter trends obtained from QuikSCAT, a classification of multi-year ice is obtained which is dependent on the day of the year (DOY). Validation of the …

Efficient Application Programming Interface For Multi-Dimensional Modeling Data, Norman L. Jones, Robert M. Wallace, Russell Jones, Cary Butler, Alan Zundel

Faculty Publications

This paper describes an Application Programming Interface (API) for managing multi-dimensional data produced for water resource computational modeling that is being developed by the US Army Engineer Research and Development Center (ERDC), in conjunction with Brigham Young University. This API, along with a corresponding data standard, is being implemented within ERDC computational models to facilitate rapid data access, enhanced data compression and data sharing, and cross-platform independence. The API and data standard are known as the eXtensible Model Data Format (XMDF), and version 1.3 is available for free download. This API is designed to manage geometric data associated with grids, …

Microstructure And Transport Properties Of Porous Li-Ion Electrodes, David E. Stephenson

Theses and Dissertations

The goal of this work is to understand the relationships between electrode microstructure and mass transport resistances. One can use this information to predict cell performance from fundamental principles. This work includes new types of particle-scale 3D models for correlating and predicting the effects of electrode microstructure on both ionic and electronic transport. The 3D models imitate the sub-micrometer-scale arrangement of active material particles, carbon, binder, and pores and use FIB/SEM images as a basis for parameterization. The 3D models are based respectively on the statistical mechanics techniques of molecular dynamics and Monte Carlo. The approach closely related to molecular …

Hexahedral Mesh Refinement Using An Error Sizing Function, Gaurab Paudel

Theses and Dissertations

The ability to effectively adapt a mesh is a very important feature of high fidelity finite element modeling. In a finite element analysis, a relatively high node density is desired in areas of the model where there are high error estimates from an initial analysis. Providing a higher node density in such areas improves the accuracy of the model and reduces the computational time compared to having a high node density over the entire model. Node densities can be determined for any model using the sizing functions based on the geometry of the model or the error estimates from the …

Compressibility Effects Of Extended Formation Flight, Andrew Ning, Ilan Kroo

Faculty Publications

Aircraft flown in formations may realize significant reductions in induced drag by flying in regions of wake upwash. However, most transports fly at transonic speeds and compressibility effects in formation flight are not well understood. This study uses an Euler solver to analyze the inviscid aerodynamic forces and moments of transonic wing/body configurations flying in a 2-aircraft formation. We consider formations with large streamwise separation distances (10-50 wingspans) in an arrangement we term extended formation flight. Compressibility-related drag penalties in formation flight may be eliminated by slowing 2-3% below the nominal out-of-formation drag divergence Mach number, at fixed lift coefficient …

Byu Indoor Flight System Circa June 2011, John C. Macdonald, Robert Leishman

Faculty Publications

This report documents the state of our indoor flight platform as of June 2011, the time of its first flight without a human in the loop. The report is intended to give enough detail that someone might have a reasonable hope of replicating our work from scratch.

Thermodynamics Of Dna Hybridization On Surfaces, Terry J. Schmitt, Thomas A. Knotts Iv

Faculty Publications

Hybridization of single-stranded DNA (ssDNA) targets to surface-tethered ssDNA probes was simulated using an advanced coarse-grain model to identify key factors that influence the accuracy of DNA microarrays. Comparing behavior in the bulk and on the surface showed, contrary to previous assumptions, that hybridization on surfaces is more thermodynamically favorable than in the bulk. In addition, the effects of stretching or compressing the probe strand were investigated as a model system to test the hypothesis that improving surface hybridization will improve microarray performance. The results in this regard indicate that selectivity can be increased by reducing overall sensitivity by a …

The Passive Load-Bearing Capacity Of The Human Lumbar Spine In The Neutral Standing Posture, Shaun B. Jeffs

Theses and Dissertations

The human lumbar spine has been shown to support compressive loads of 1000 N in standing and walking, and up to many thousands of Newtons in strenuous activities such as lifting. The literature presents a number of biomechanical models that seek to replicate the load-carrying capacity of the spine while adhering to physiological constraints. While many of these models provide invaluable insights into the mechanisms governing spinal stability, there is a nearly universal disregard for the magnitude of the muscle forces required in the neutral standing posture. In compliance with constraints on metabolic cost and muscle fatigue, muscle activations in …

Soap Bubbles And Solid Spheres: Collisions And Interactions, Joshua A. Bryson

Theses and Dissertations

Under the right conditions, a moving sphere may successfully enter, and leave, a soap bubble without rupturing that bubble. The physics behind this phenomena are not well understood, nor the limiting factors (such as sphere size, speed, etc.). This work, investigating this phenomenon using high speed photography, has produced several results which are presented. First, several distinct regimes, noted while photographing the interactions between the spheres and the bubbles, are classified and discussed. Next a probabilistic examination of the soap bubbles rupture by the moving spheres is presented. Then a conjecture for the limiting sphere sizes and speeds is presented. …

Effects Of Tethering A Multistate Folding Protein To A Surface, Shuai Wei, Thomas A. Knotts Iv

Faculty Publications

Protein/surface interactions are important in a variety of fields and devices, yet fundamental understanding of the relevant phenomena remains fragmented due to resolution limitations of experimental techniques. Molecular simulation has provided useful answers, but such studies have focused on proteins that fold through a two-state process. This study uses simulation to show how surfaces can affect proteins which fold through a multistate process by investigating the folding mechanism of lysozyme (PDB ID: 7LZM). The results demonstrate that in the bulk 7LZM folds through a process with four stable states: the folded state, the unfolded state, and two stable intermediates. The …

Dynamics Of A Partially Fluid-Filled Sphere, Jeff Hendricks, Taylor W. Killian, Robert A. Klaus, Nick Smith, Tadd T. Truscott

Faculty Publications

We introduce a study on the slosh dynamics of a partially filled elastic sphere. Currently the physical design of fluid-filled containers utilizes clever construction and machinery to mitigate sloshing motions. There are numerous cases that have been observed but we focus on the impact of a sphere under free fall with an initially undisturbed free surface. The study focuses on measurement and simulation of the force distribution between the fluid and the sphere through the use of high-speed imaging and finite element analysis. Using the cavity shape data, a potential flow numerical model is developed that predicts the unsteady forces. …

Observability Analysis Of Cooperative Localization Using Graph Theory And Lie Derivatives, Rajnikant Sharma

Faculty Publications

In this report we derive the observability matrix for an edge between two robots and an edge between a robot and a landmark.

Aerodynamic Performance Of Extended Formation Flight, Andrew Ning, Tristan Flanzer, Ilan Kroo

Faculty Publications

Close formation flight is of limited practicality for commercial aviation. Our concept of extended formation flight takes advantage of the persistence of cruise wakes by extending the streamwise spacing between aircraft in a formation. This allows the aircraft to fly at safe separation distances from each other, while still benefiting from the upwash of the upstream wake(s). In this paper we are interested in estimating the performance of these extended formations, and estimating some of the effects that limit the longitudinal extent of the formation. We consider the effects of wake rollup, vortex decay, vortex instabilities, vortex motion, and atmospheric …

Advancements In The Solid-State Impact-Ionization Multiplier (Sim) Through Theory, Simulation And Design, Michael S. Johnson

Theses and Dissertations

This dissertation outlines the study and development of a Solid-state Impact-ionization Multiplier (SIM). The SIM is a stand-alone current amplifier designed with optical detection systems in mind. The SIM amplifies signals utilizing impact ionization as a source of gain. The SIM is fabricated on silicon in order to take advantage of its favorable impact ionization coefficients. Utilizing silicon in impact ionization based gain devices makes low noise and high gains attainable. Because it is a stand-alone device, it can be wired to an arbitrary current source making it capable of receiving an input from photodiodes of any material. This makes …

Experimental Study Of Liquid Squeeze-Flow As It Relates To Human Voice Production, Daniel Victor Lo Forte

Theses and Dissertations

Approximately 7.5 million people suffer from voice disorders in the United States. Previous studies indicate that the quality of the fluid layer that coats the vocal folds appears to be different for people with voice disorders than for people whose voice is considered normal. These studies suggest that the composition and/or physical properties of the fluid layer may contribute to voice disorders. Despite these findings, little research has been undertaken to investigate the role of the fluid layer on voice, and in almost all cases, the fluid layer is considered to be insignificant. The purpose of this research was to …