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Full-Text Articles in Engineering

A Flexible Service-Oriented Approach To Address Hydroinformatic Challenges In Large-Scale Hydrologic Predictions, Michael Antonio Souffront Alcantara Dec 2018

A Flexible Service-Oriented Approach To Address Hydroinformatic Challenges In Large-Scale Hydrologic Predictions, Michael Antonio Souffront Alcantara

Theses and Dissertations

Water security is defined as a combination of water for achieving our goals as a society, and an acceptable level of water-related risks. Hydrologic modeling can be used to predict streamflow and aid in the decision-making process with the goal of attaining water security. Developed countries usually have their own hydrologic models; however, developing countries often lack hydrologic models due to factors such as the maintenance, computational costs, and technical capacity needed to run models. A global streamflow prediction system (GSPS) would help decrease vulnerabilities in developing countries and fill gaps in areas where no local models exist by providing …

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Planar Linear Ion Traps With Microscale Radii For Portable Mass Spectrometry, Trevor Keith Decker Dec 2018

Planar Linear Ion Traps With Microscale Radii For Portable Mass Spectrometry, Trevor Keith Decker

Theses and Dissertations

Radio frequency (RF) ion traps based on the quadrupole device developed by Paul and Steinwedel utilize a dynamic electric field to spatially confine the trajectory of charged particles and may be employed as mass spectrometers by selectively ejecting trapped molecules based on the mass to charge ratio. Because of the inherent sensitivity and specificity of this process, ion trap mass spectrometers have become a popular scientific instrument. In the past two decades there has been a push to develop portable ion trap mass spectrometers for in situ mass analysis by geometrically scaling traps to smaller sizes. This decreases the power …

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5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj Dec 2018

5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj

Theses and Dissertations

Knowledge of the full 5-degree Grain Boundary Character Distribution (GBCD) is vital to understanding properties, such as gas diffusivity, that are dominated by grain boundary character. Surface characterization techniques, such as Electron Backscattered diffraction (EBSD), can provide only 4 of the 5 GB characteristics (the rotation between the neighboring grains, and the trace of the GB on the surface). The inclination of the GB in the direction normal to the surface is not known. A previous study indicated that the GB inclination could be recovered by correlating the Electron Backscattered patterns (EBSPs) of sample points near the GB with EBSPs …

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Assuring Intellectual Property Through Physical And Functional Comparisons, Adam Kendall Hastings Dec 2018

Assuring Intellectual Property Through Physical And Functional Comparisons, Adam Kendall Hastings

Theses and Dissertations

Hardware trojans pose a serious threat to trusted computing. However, hardware trojan detection methods are both numerous and onerous, making hardware trojan detection a difficult and time-consuming procedure. This thesis introduces the IP Assurance Framework, which drastically improves the time it takes design teams to test for hardware trojans. The IP Assurance Framework is implemented in two ways: The first method, Physical Assurance, compares instantiated IP blocks to a golden model via physical-level comparisons, while the second method, Functional Assurance, compares IP to a golden model using logical-level comparisons. Both methods are demonstrated to distinguish between tampered and untampered IP …

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Analysis Of The Effects Of Inlet Distortion On Stall Cell Formation In A Transonic Compressor Using Create-Av Kestrel, Mikkel Andreas Unrau Dec 2018

Analysis Of The Effects Of Inlet Distortion On Stall Cell Formation In A Transonic Compressor Using Create-Av Kestrel, Mikkel Andreas Unrau

Theses and Dissertations

Accurately predicting fan performance, including bounds of operation, is an important function of any Computational Fluid Dynamics (CFD) package. The presented research uses a CFD code developed as part of the Computational Research and Engineering Acquisition Tools and Environment (CREATE), known as Kestrel, to evaluate a single stage compressor at various operating conditions. Steady-state, single-passage simulations are carried out to validate capabilities recently added to Kestrel. The analysis includes generating speedlines of total pressure ratio and efficiency, as well as radial total temperature and total pressure profiles at two axial locations in the compressor at various operating conditions and fan …

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Swat Online: Development Of A Web-Based Decision Support System For The Soil And Water Assessment Tool, Spencer Dean Mcdonald Dec 2018

Swat Online: Development Of A Web-Based Decision Support System For The Soil And Water Assessment Tool, Spencer Dean Mcdonald

Theses and Dissertations

As satellite and climate modelling technology continues to improve and as climatological disasters and issues continue to impact the global community, climate data will increase in size and relevance. With this new influx of information, it is becoming more and more important for scientists to simply and concisely communicate their findings to both decision makers in governments and disaster preparedness organizations and also to the general public. The Soil and Water Assessment Tool (SWAT) is a powerful modelling tool that allows scientists to simulate essentially all of the physical processes involved in the water cycle. The data that SWAT produces …

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Flight Vehicle Design, Andrew Ning Dec 2018

Flight Vehicle Design, Andrew Ning

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No abstract provided.

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Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson Dec 2018

Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson

Theses and Dissertations

An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one outlier at …

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Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau Dec 2018

Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau

Theses and Dissertations

Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for …

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Rapid Separation Of Bacteria From Blood For Sepsis Diagnosis, Mahsa Alizadeh Dec 2018

Rapid Separation Of Bacteria From Blood For Sepsis Diagnosis, Mahsa Alizadeh

Theses and Dissertations

Sepsis is a severe blood infection caused by bacteria entering the blood stream. Sepsis caused by antibiotic resistant bacteria is very dangerous with a high mortality rate. The current clinical diagnostic methods for sepsis require culturing the blood sample prior to other steps of the diagnosis procedure. Culturing the blood samples is a time-consuming step which increases the time required for the diagnostic procedure. Considering the fact that the mortality rate of the sepsis increases as time passes, it is essential to find methods for sepsis diagnosis that do not require culturing the samples. The first step of a new …

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Development Of A Simplified Analysis Approach For Predicting Pile Deflections Of Piers Subjected To Lateral Spread Displacements And Application To A Pier Damaged During The 2010 Maule, Chile, M8.8 Earthquake, Logan Matthew Palmer Dec 2018

Development Of A Simplified Analysis Approach For Predicting Pile Deflections Of Piers Subjected To Lateral Spread Displacements And Application To A Pier Damaged During The 2010 Maule, Chile, M8.8 Earthquake, Logan Matthew Palmer

Theses and Dissertations

The 2010, moment magnitude 8.8 earthquake that occurred near Maule, Chile caused major damages to several piers in the Port of Coronel located approximately 160 kilometers (100 miles) to the South of the earthquake epicenter. One of the piers, the North Pier, experienced significant lateral spreading that was caused from liquefaction of the soils at the approach zone of the pier. Damages from lateral spreading and liquefaction effects consisted of sheet pile welding ruptures of the cross-support beams, stiffener buckling, pile displacements, pile rotations, and pier deck displacement. Researchers analyzed the North Pier after the earthquake and documented in detail …

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Optimization-Based Spatial Positioning And Energy Management For Unmanned Aerial Vehicles, Ronald Abraham Martin Dec 2018

Optimization-Based Spatial Positioning And Energy Management For Unmanned Aerial Vehicles, Ronald Abraham Martin

Theses and Dissertations

This research applies techniques from the field of optimization to spatial positioning and energy management in Unmanned Aerial Vehicles (UAVs). Two specific areas are treated: optimization of UAV view plans for 3D modeling of infrastructure, and trajectory optimization of solar powered high-altitude long-endurance (HALE) UAVs. Structure-from-Motion (SfM) is a computer vision technique for creating 3D models from 2D images. View planning is the process of planning image sets that will effectively model a given scene. First, a genetic algorithm based view planning approach is demonstrated. A novel terrain simulation environment is developed, and the algorithm is tested at multiple sites …

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Large-Scale Non-Linear Dynamic Optimization For Combining Applications Of Optimal Scheduling And Control, Logan Daniel Beal Dec 2018

Large-Scale Non-Linear Dynamic Optimization For Combining Applications Of Optimal Scheduling And Control, Logan Daniel Beal

Theses and Dissertations

Optimization has enabled automated applications in chemical manufacturing such as advanced control and scheduling. These applications have demonstrated enormous benefit over the last few decades and continue to be researched and refined. However, these applications have been developed separately with uncoordinated objectives. This dissertation investigates the unification of scheduling and control optimization schemes. The current practice is compared to early-concept, light integrations, and deeper integrations. This quantitative comparison of economic impacts encourages further investigation and tighter integration. A novel approach combines scheduling and control into a single application that can be used online. This approach implements the discrete-time paradigm from …

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Pore Pressure Generation And Shear Modulus Degradation During Laminar Shear Box Testing With Prefabricated Vertical Drains, Landon Scott Kinney Dec 2018

Pore Pressure Generation And Shear Modulus Degradation During Laminar Shear Box Testing With Prefabricated Vertical Drains, Landon Scott Kinney

Theses and Dissertations

Liquefaction is a costly phenomenon where soil shear modulus degrades as the generation of excess pore pressures begins. One of the methods to mitigate liquefaction, is the use of prefabricated vertical drains. Prefabricated vertical drains provide a drainage path to effectively mitigate the generation of pore pressures and aid in shear modulus recovery. The aims of this study were to define shear modulus degradation vs. shear strain as a function of excess pore pressure ratio; define the effects of prefabricated vertical drains on the behavior of pore pressure generation vs. shear strain; and to define volumetric strain as a function …

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Two-Phase Interactions On Superhydrophobic Surfaces, Kimberly Ann Stevens Dec 2018

Two-Phase Interactions On Superhydrophobic Surfaces, Kimberly Ann Stevens

Theses and Dissertations

Superhydrophobic surfaces have gained attention as a potential mechanism for increasing condensation heat transfer rates. Various aspects related to condensation heat transfer are explored. Adiabatic, air-water mixtures are used to explore the influence of hydrophobicity on two-phase flows and the hydrodynamics which might be present in flow condensation environments. Pressure drop measurements in a rectangular channel with one superhydrophobic wall (cross-section approximately 0.37 X 10 mm) are obtained, revealing a reduction in the pressure drop for two-phase flow compared to a control scenario. The observed reduction is approximately 10% greater than the reduction that is observed for single-phase flow (relative …

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Property Localization For Grain Boundary Diffusivity Via Inverse Problem Theory, Christian Kurniawan Dec 2018

Property Localization For Grain Boundary Diffusivity Via Inverse Problem Theory, Christian Kurniawan

Theses and Dissertations

The structure and spatial arrangement of grain boundaries strongly affect the properties of polycrystalline materials such as corrosion, creep, weldability, superconductivity, and diffusivity. However, constructing predictive grain boundary structure-property models is taxing, both experimentally and computationally due to the high dimensionality of the grain boundary character space. The purpose of this work is to develop an effective method to infer grain boundary structure-property models from measurement of the effective properties of polycrystals by utilizing the inverse problem theory. This study presents an idealized case in which structure-property models for grain boundary diffusivity are inferred from a noisy simulation. The method …

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Strength Investigation Of Damaged And Repaired Thin-Walled Composite Structures, Analise Barlow Dec 2018

Strength Investigation Of Damaged And Repaired Thin-Walled Composite Structures, Analise Barlow

Theses and Dissertations

The purpose of this research was to quantify the strength of novel composite repair methods for thin-walled composite structures. Carbon/epoxy plates were manufactured and repairs were made at Gloyer-Taylor Laboratories. At BYU, specimens were damaged in a controlled and repeatable process. Three damage modes were implemented: impact, groove, and abrasive damage. Tensile strength tests were performed on control, damaged, and repaired specimens. Four 24 x 24 in (60 x 60 cm) carbon/epoxy plates were received. Each plate was made up of seven plies cured together with epoxy resin for a nominal total thickness of 0.04 in (1.02 mm). The thickness, …

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Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, R. Abraham Martin, Nathaniel S. Gates, Andrew Ning, John Hedengren Nov 2018

Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, R. Abraham Martin, Nathaniel S. Gates, Andrew Ning, John Hedengren

Faculty Publications

This paper demonstrates the use of nonlinear dynamic optimization to calculate energy-optimal trajectories for a high-altitude, solar-powered unmanned aerial vehicle (UAV). The objective is to maximize the total energy in the system while staying within a 3 km mission radius and meeting other system constraints. Solar energy capture is modeled using the vehicle orientation and solar position, and energy is stored both in batteries and in potential energy through elevation gain. Energy capture is maximized by optimally adjusting the angle of the aircraft surface relative to the sun. The UAV flight and energy system dynamics are optimized over a 24 …

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Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Ronald Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren Nov 2018

Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Ronald Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren

Faculty Publications

This paper demonstrates the use of nonlinear dynamic optimization to calculate energy optimal trajectories for a high-altitude, solar-powered Unmanned Aerial Vehicle (UAV). The objective is to maximize the total energy in the system while staying within a 3 km mission radius and meeting other system constraints. Solar energy capture is modeled using the vehicle orientation and solar position, and energy is stored both in batteries and in potential energy through elevation gain. Energy capture is maximized by optimally adjusting the angle of the aircraft surface relative to the sun. The UAV flight and energy system dynamics are optimized over a …

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Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore Nov 2018

Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore

Theses and Dissertations

While vertical takeoff and landing aircraft show promise for urban air transport, distributed electric propulsion on existing aircraft may offer an immediately implementable alternative. Dis- tributed electric propulsion has the potential of increasing the aircraft thrust-to-weight ratio and lift coefficient high enough to enable takeoff distances of less than 100 meters. While fuel based propulsion technologies generally increase in specific power with increasing size, electric propul- sion typically can be decreased in size without a decrease in specific power. The smaller but highly power-dense propulsion units enable alternative designs including many small units, optionally powered units, and vectored thrust from …

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Frequency Response Of The Leap Motion Controller And Its Suitability For Measuring Tremor, Clay J. Kincaid, Austin C. Vaterlaus, Nathan R. Stanford, Steven Knight Charles Nov 2018

Frequency Response Of The Leap Motion Controller And Its Suitability For Measuring Tremor, Clay J. Kincaid, Austin C. Vaterlaus, Nathan R. Stanford, Steven Knight Charles

Faculty Publications

Although tremor is one of the most common movement disorders, it is evaluated using relatively coarse clinical scales. We propose to measure tremor in clinical settings using the Leap Motion Controller (LMC), which is a markerless motion capture sensor that has a low cost, zero set-up time, and dynamic accuracy of 1.2mm. However, the frequency response of the LMC has not been characterized, so its ability to track oscillations such as tremor is unknown. To characterize the frequency response of the LMC, we measured the position of a mannequin hand simultaneously with the LMC and a high-resolution encoder while the …

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Characterizing Interfacial Bonds In Hybrid Metal Am Structures, John Ross Linn Nov 2018

Characterizing Interfacial Bonds In Hybrid Metal Am Structures, John Ross Linn

Theses and Dissertations

The capabilities of various metal Additive Manufacturing (AM) processes, such as Powder Bed Fusion – Laser (PBF-L) and Direct Energy Deposition (DED) are increasing such that it is becoming ever more common to use them in industrial applications. The ability to print atop a substrate broadens that scope of applications. There is ongoing research regarding the mechanical properties of additively processed materials, but little regarding the interaction between additive material and its substrate. An understanding of the mechanical and performance properties of the AM/substrate interface is imperative. This paper describes a study of the strength properties of AM/substrate interfaces, with …

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Pvt-Tolerant Stochastic Time-To-Digital Converter, Khalil Jacob Gammoh Nov 2018

Pvt-Tolerant Stochastic Time-To-Digital Converter, Khalil Jacob Gammoh

Theses and Dissertations

Time-to-digital converters (TDC) are widely used in light-detection-and-ranging (LIDAR) systems to measure the time-of-flight. Conventional TDCs are sensitivity to process, voltage, and temperature (PVT) variations. Recent work utilizing the stochastic delay-line TDC architecture has demonstrated excellent robustness against PVT variations. But important issues affecting the linearity of a stochastic delay-line TDC has yet to be recognized and addressed.This thesis rigorously analyzes the problem of linearity of a stochastic delay-line TDC and formulates an intuitive theory to predict the linearity performance. Apolarvisualization of the phase distribution of a delay line is proposed to aid the analysis. Based on the results of …

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3d Printing For Microfluidics, Hua Gong Nov 2018

3d Printing For Microfluidics, Hua Gong

Theses and Dissertations

This dissertation focuses on developing 3D printing as a fabrication method for microfluidic devices. Specifically, I concentrate on the 3D printing approach known as Digital Light Processing stereolithography (DLP-SLA) in which serially projected images are used to sequentially photopolymerize layers to build a microfluidic device. The motivation for this work is to explore a much faster alternative to cleanroom-based microfabrication that additionally offers the opportunity to densely integrate microfluidic elements in compact 3D layouts for dramatic device volume reduction. In the course of my research, an optical approach was used to guide custom resin formulation to help create the interconnected …

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Correlating Easily And Unobtrusively Queried Computer Characteristics To Number And Severity Of Vulnerabilities, Jonathan M. Mercado Nov 2018

Correlating Easily And Unobtrusively Queried Computer Characteristics To Number And Severity Of Vulnerabilities, Jonathan M. Mercado

Theses and Dissertations

Cybersecurity has become a top-of-mind concern as the threat landscape expands and organizations continue to undergo digital transformation. As the industry confronts this growth, tools designed to evaluate the security posture of a network must improve to provide better value. Current agent-based and network scanning tools are resource intensive, expensive, and require thorough testing before implementation in order to ensure seamless integration. While surfacing specific vulnerability information is imperative to securing network assets, there are ways to predict the security status of a network without taking exact measurements. These methods may inform security professionals as to where the weakest points …

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Modeling Soot Formation Derived From Solid Fuels, Alexander Jon Josephson Nov 2018

Modeling Soot Formation Derived From Solid Fuels, Alexander Jon Josephson

Theses and Dissertations

Soot formation from complex solid fuels, such as coal or biomass, is an under-studied and little understood phenomena which has profound physical effects. Any time a solid fuel is combusted, from coal-burning power plants to wildland fires, soot formation within the flame can have a significant influence on combustion characteristics such as temperature, heat flux, and chemical profiles. If emitted from the flame, soot particles have long-last effects on human health and the environment. The work in this dissertation focuses on creating and implementing computational models to be used for predicting soot mechanisms in a combustion environment. Three models are …

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Vision-Based Emergency Landing Of Small Unmanned Aircraft Systems, Parker Chase Lusk Nov 2018

Vision-Based Emergency Landing Of Small Unmanned Aircraft Systems, Parker Chase Lusk

Theses and Dissertations

Emergency landing is a critical safety mechanism for aerial vehicles. Commercial aircraft have triply-redundant systems that greatly increase the probability that the pilot will be able to land the aircraft at a designated airfield in the event of an emergency. In general aviation, the chances of always reaching a designated airfield are lower, but the successful pilot might use landmarks and other visual information to safely land in unprepared locations. For small unmanned aircraft systems (sUAS), triply- or even doubly-redundant systems are unlikely due to size, weight, and power constraints. Additionally, there is a growing demand for beyond visual line …

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Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren Nov 2018

Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren

Faculty Publications

This paper demonstrates the use of nonlinear dynamic optimization to calculate energy- optimal trajectories for a high-altitude, solar-powered Unmanned Aerial Vehicle (UAV). The objective is to maximize the total energy in the system while staying within a 3 km mission radius and meeting other system constraints. Solar energy capture is modeled using the vehicle orientation and solar position, and energy is stored both in batteries and in potential energy through elevation gain. Energy capture is maximized by optimally adjusting the angle of the aircraft surface relative to the sun. The UAV flight and energy system dynamics are optimized over a …

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Analysis Of Particle Behavior Inside The Classifier Of A Raymond Bowl Mill While Co-Milling Woody Biomass With Coal, Seyedhassan Fakourian, Andrew R. Fry, Tanner Jasperson Oct 2018

Analysis Of Particle Behavior Inside The Classifier Of A Raymond Bowl Mill While Co-Milling Woody Biomass With Coal, Seyedhassan Fakourian, Andrew R. Fry, Tanner Jasperson

Faculty Publications

Woody biomass cofiring with coal at existing pulverized-coal boilers is known to be a green energy source and is a low-expense alternative for pure coal combustion. Co-milling woody biomass particles (15 wt%) with coal particles (85 wt%) before burning at a boiler is a complex problem because large woody biomass particles (>300 μm) exit the milling system along with the fine particles. A Computational Particle Fluid Dynamics (CPFD) is used in this paper to present a novel analysis about the behavior of woody biomass particles as they are mixed with coal particles inside the classifier. To meet this …

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An Investigation Of Engineering Design Cognition And Achievement In Primary School, Greg J. Strimel, Scott R. Bartholomew, Eunhye Kim, Liwei Zhang Oct 2018

An Investigation Of Engineering Design Cognition And Achievement In Primary School, Greg J. Strimel, Scott R. Bartholomew, Eunhye Kim, Liwei Zhang

Faculty Publications

This study examined the design cognition and achievement results of both kindergarten and fourth grade students engaged in engineering design-based instructional activities. Relationships between design cognition and student grade level, as well as quality of student work, were investigated. 30 concurrent think-aloud protocols were collected from individual primary students as they worked in groups to design and make a solution to a design task. The concurrent think-aloud protocols were examined and coded to determine the duration of time the participants devoted to a pre-established set of mental processes for technological problem solving. Significant differences between kindergarten and fourth grade participants …

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