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Articles 931 - 960 of 4850

Full-Text Articles in Engineering

Real Time Design Space Exploration Of Static And Vibratory Structural Responses In Turbomachinery Through Surrogate Modeling With Principal Components, Spencer Reese Bunnell Jun 2020

Real Time Design Space Exploration Of Static And Vibratory Structural Responses In Turbomachinery Through Surrogate Modeling With Principal Components, Spencer Reese Bunnell

Theses and Dissertations

Design space exploration (DSE) is used to improve and understand engineering designs. Such designs must meet objectives and structural requirements. Design improvement is non-trivial and requires new DSE methods. Turbomachinery manufacturers must continue to improve existing engines to keep up with global demand. Two challenges of turbomachinery DSE are: the time required to evaluate designs, and knowing which designs to evaluate. This research addressed these challenges by developing novel surrogate and principal component analysis (PCA) based DSE methods. Node and PCA-based surrogates were created to allow faster DSE of turbomachinery blades. The surrogates provided static stress estimation within 10% error. …


Electrochemical Sensors Enhanced By Convection And By 3d Arrays Of Vertically Aligned Carbon Nanotubes, Benjamin James Brownlee Jun 2020

Electrochemical Sensors Enhanced By Convection And By 3d Arrays Of Vertically Aligned Carbon Nanotubes, Benjamin James Brownlee

Theses and Dissertations

Early and accessible diagnostics are important elements to reducing the negative side-effects of untreated disease. One key advancement in diagnostic monitoring is through the development of highly sensitive sensors that have the capability to detect lower concentrations, while still remaining accessible for point-of-care use. This dissertation characterizes electrochemical sensing platforms that are enhanced by convection and by 3D electrodes made from high surface area, vertically aligned carbon nanotubes (VACNTs). Free-standing VACNTs were patterned into microchannel arrays for flow-through amperometric sensing. Convective mass transfer enhancement was shown to improve sensor performance in amperometric sensing through the use of high surface area …


Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt Jun 2020

Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt

Theses and Dissertations

This dissertation is focused on the modeling and robust model-based control of high degree-of-freedom (DoF) systems. While most of the contributions are applicable to any difficult-to-model system, this dissertation focuses specifically on applications to large-scale soft robots because their many joints and pressures constitute a high-DoF system and their inherit softness makes them difficult to model accurately. First a joint-angle estimation and kinematic calibration method for soft robots is developed which is shown to decrease the pose prediction error at the end of a 1.5 m robot arm by about 85\%. A novel dynamic modelling approach which can be evaluated …


Roof Material Suitability For It Mission-Critical Facilities, Charles Akira Petrinovich Jun 2020

Roof Material Suitability For It Mission-Critical Facilities, Charles Akira Petrinovich

Theses and Dissertations

Mission-critical facilities house operations that when interrupted, can prove disastrous to an organization’s future. Limited market research is available to determine what roof types are best suited to meet the unique demands of these buildings. The purpose of this research was to evaluate different roof materials and to observe trends relative to their lifecycle costs and roof professional’s assessment in use with mission-critical facilities. The objectives of the study were to determine the average annual lifecycle costs for the sampled roof materials, to determine the roofing professionals’ preferred mission-critical facility roof materials, and to priority rank the sampled roof materials …


Model Predictive Control And Estimation Of Managed Pressure Drilling Using A Real-Time High Fidelity Flow Model, Junho Park, Cameron Price, David Pixton, Manuel Aghito, Roar Nybø, Knut Bjørkevoll, John Hedengren May 2020

Model Predictive Control And Estimation Of Managed Pressure Drilling Using A Real-Time High Fidelity Flow Model, Junho Park, Cameron Price, David Pixton, Manuel Aghito, Roar Nybø, Knut Bjørkevoll, John Hedengren

Faculty Publications

When drilling an oil or gas well, well pressures may be controlled using a technology called managed pressure drilling. This technology often relies on model predictive control schemes; however, practical limitations have generally led to the use of simplified controller models that do not optimally handle certain perturbations in the physical system. The present work reports on the first implementation of a highly accurate system model that has been adapted for real-time use in a controller. This real-time high-fidelity model approximates the results of offline high-fidelity models without requiring operation by model experts. The effectiveness of the model is demonstrated …


Trading Up: Exchanging Our Data For A Better Life, Nathan Turner May 2020

Trading Up: Exchanging Our Data For A Better Life, Nathan Turner

Marriott Student Review

We live in a data-driven economy. Many people feel like consumers are on the losing end of an economic data-battle with tech giants, but this is simply not true; our data can drive innovation. That’s right—personal data collected from you and me can influence new technologies that will improve our lives. This should excite us, but our fear of losing data privacy can quell our excitement for progress and even restrict innovation. Our quality of life has already begun to improve through data driven innovation, and technological progress is not slowing down. If we let our fear of losing data …


New Policies Give Solar Users An Economic Boost, Olivia Fowler May 2020

New Policies Give Solar Users An Economic Boost, Olivia Fowler

Marriott Student Review

The future looks bright for Solar Energy, as more States and Territories in the United States commit to moving to 100% renewable energy. What are the different states and territories committing to exactly, and what economic incentives are they bringing? Find out in this article by author Olivia Fowley.


Chemical And Thermal Sintering Of Supported Metals With Emphasis On Cobalt Catalysts During Fischer−Tropsch Synthesis, Mahmood Rahmati, Mohammad-Saeed Safdari, Thomas H. Fletcher, Morris D. Argyle, Calvin H. Bartholomew May 2020

Chemical And Thermal Sintering Of Supported Metals With Emphasis On Cobalt Catalysts During Fischer−Tropsch Synthesis, Mahmood Rahmati, Mohammad-Saeed Safdari, Thomas H. Fletcher, Morris D. Argyle, Calvin H. Bartholomew

Faculty Publications

This comprehensive critical review combines, for the first time, recent advances in nanoscale surface chemistry, surface science, DFT, adsorption calorimetry, and in situ XRD and TEM to provide new insights into catalyst sintering. This work provides qualitative and quantitative estimates of the extent and rate of sintering as functions of nanocrystal (NC) size, temperature, and atmosphere. This review is unique in that besides summarizing important, useful data from previous studies, it also advances the field through addition of (i) improved or new models, (ii) new data summarized in original tables and figures, and (iii) new fundamental perspectives into sintering of …


Silicone 3d Printing Processes For Fabricating Synthetic, Self-Oscillating Vocal Fold Models, Taylor Eugene Greenwood May 2020

Silicone 3d Printing Processes For Fabricating Synthetic, Self-Oscillating Vocal Fold Models, Taylor Eugene Greenwood

Theses and Dissertations

Synthetic, self-oscillating vocal fold (VF) models are physical models whose life-like vibration is induced and perpetuated by fluid flow. Self-oscillating VF models, which are often fabricated life-size from soft silicone elastomers, are used to study various aspects of voice biomechanics. Despite their many advantages, the development and use of self-oscillating VF models is limited by the casting process used to fabricate the models. Consequently, this thesis focuses on the development of 3D printing processes for fabricating silicone VF models. A literature review is first presented which describes three types of material extrusion 3D printing processes for silicone elastomers, namely direct …


Impact Of Part Thickness And Drying Conditions On Saturation Limits In Binder Jet Additive Manufacturing, Nathan B. Crane May 2020

Impact Of Part Thickness And Drying Conditions On Saturation Limits In Binder Jet Additive Manufacturing, Nathan B. Crane

Faculty Publications

Binder jetting (BJ) is a high build-rate additive manufacturing process with growing commercial interest. Growth in BJ applications is driven by the use of finer powders and improved post-processing methods that can produce dense, homogenous final parts. However, understanding of the basic droplet/powder interaction is relatively limited. This paper considers the impact of in-process drying, part geometry, and droplet size on a key printing parameter: binder saturation. Parts of varying thicknesses are printed with a range of saturation levels under various heating conditions. The ratio of the printed part mass to the theoretical part mass is used to detect bleeding. …


Turbulence Modulation In Particle-Laden Stationary Homogeneous Isotropic Turbulence Using One-Dimensional Turbulence, Marco Fistler, Alan Kerstein, David O. Lignell, Michael Oevermann Apr 2020

Turbulence Modulation In Particle-Laden Stationary Homogeneous Isotropic Turbulence Using One-Dimensional Turbulence, Marco Fistler, Alan Kerstein, David O. Lignell, Michael Oevermann

Faculty Publications

Turbulence modulation in particle-laden stationary homogeneous isotropic turbulence is investigated using one-dimensional turbulence (ODT), a low-dimensional stochastic flow simulation model. For this purpose, ODT is extended in two ways. First, a forcing scheme that maintains statistical stationarity is introduced. Unlike direct numerical simulation (DNS) of forced turbulence, the ODT framework accommodates forcing that is not directly coupled to the momentum equation. For given forcing the ODT energy dissipation rate is therefore the same in particle-laden cases as in the corresponding single-phase reference case. Second, previously implemented one-way-coupled particle phenomenology is extended to two-way coupling using the general ODT methodology for …


Gas-Solid Reaction Pathway For Chlorination Of Rare Earth And Actinide Metals Using Hydrogen And Chlorine Gas, Parker Okabe, Matthew Newton, Devin Rappleye, Michael F. Simpson Apr 2020

Gas-Solid Reaction Pathway For Chlorination Of Rare Earth And Actinide Metals Using Hydrogen And Chlorine Gas, Parker Okabe, Matthew Newton, Devin Rappleye, Michael F. Simpson

Faculty Publications

Hydriding and chlorination of buttons of metallic cerium have been tested as a head-end step to separating metal impurities from actinides. The objective was to achieve complete conversion to chlorides while maintaining high surface area via small particles and open porosity. Hydriding by reaction with 100% H2 gas at 573 K was successful at reducing cm-scale metal buttons into small particles/fragments. This step was followed by reaction with flowing 99.5% anhydrous Cl2 gas at temperatures ranging from 423 to 573 K for 60 min. In experiments reported here, up to 92% conversion to cerium chloride was achieved from reacting with …


In Vivo Silicon Lance Array Transfection Of Plant Cells, Taylor Andrew Brown Apr 2020

In Vivo Silicon Lance Array Transfection Of Plant Cells, Taylor Andrew Brown

Theses and Dissertations

Arrays of silicon lances were made using photolithographic and STS DRIE Bosch techniques. Arrays consist of a 10 mm square grid pattern of lances measuring 100 m tall and having a 3 mm diameter, each lance being spaced 30 mm apart. The tips of lances are pointed, allowing easier penetration through plant cell walls. A nanoinjector device was also made to accept the silicon lance arrays and perform nanoinjections. A nanoinjection consisted of 2 silicon lance arrays, with lances oriented towards each other, being moved into and out of a plant cotyledon placed between them. Prior to the nanoinjection, polar …


Polyester Polymer Concrete For Bridge Deck Overlays, Robert James Stevens Apr 2020

Polyester Polymer Concrete For Bridge Deck Overlays, Robert James Stevens

Theses and Dissertations

The objectives of this research were to 1) compile a synthesis of information about polyester polymer concrete (PPC) from the literature; 2) conduct a scanning tour to observe PPC construction, inspect in-service PPC overlays, and discuss topics related to PPC; 3) revise the existing Utah Department of Transportation (UDOT) PPC specification; 4) document a PPC field demonstration project; and 5) perform laboratory characterization of the material properties of field-mixed PPC. The scope of the research included a scanning tour, field testing, and laboratory experimentation. The objectives of the scanning tour included observation of a PPC overlay placement, inspection of existing …


Distributed Memory Based Fpga Debug, Robert Benjamin Hale Apr 2020

Distributed Memory Based Fpga Debug, Robert Benjamin Hale

Theses and Dissertations

Field-programmable gate arrays (FPGAs) are powerful integrated circuits for low-overhead custom computing needs and design prototyping. Due to the hardware nature of programming an FPGA, finding bugs in a design can be a very challenging process. Signals need to be physically probed and data recorded in real time. This is often done by dedicating some resources on the FPGA itself towards an embedded logic analyzer. This method is effective but can be time and resource consuming. Academic research projects have produced a variety of methods for reducing this difficulty. One option that has previously been unexplored is the use of …


High-Speed Apparatus And Signal Processing For Accoustic Delamination Detection On Concrete Bridge Decks, Lorin James Hendricks Apr 2020

High-Speed Apparatus And Signal Processing For Accoustic Delamination Detection On Concrete Bridge Decks, Lorin James Hendricks

Theses and Dissertations

Maintenance and repair of deteriorating civil infrastructure are global problems requiring significant attention and resources. Accurate measurements of civil infrastructure enable lower repair and rehabilitation costs if mitigation techniques are deployed at earlier stages of deterioration. This research describes an infrastructure inspection solution to scan concrete bridge decks for internal cracking at high speeds. Internal cracking within bridge decks, known as delamination, is a particularly difficult defect to identify because it is often not detectable through visual inspection. State-of-the practice testing approaches involve the use of slow and subjective manual sounding techniques and costly lane closures. The need for an …


Assessing Levels Of Corrosion On Extracted Mse Wall Reinforcement, Robert Ashton Thompson Apr 2020

Assessing Levels Of Corrosion On Extracted Mse Wall Reinforcement, Robert Ashton Thompson

Theses and Dissertations

The purpose of this study was to extract galvanized steel wire reinforcement coupons from mechanically stabilized earth (MSE) walls along I-15 and determine the rate of corrosion that has taken place since Phase I, which was conducted by Gerber and Billings (2010). The galvanized steel reinforcement analyzed in this study has been in place for 19 to 20 years at the time of extraction. A total of 85 coupons were extracted and laboratory analysis was performed to determine the thickness of remaining zinc galvanization on each coupon. Soil samples were obtained from each one-stage wall extraction location to determine moisture …


Narrow Angle Radiometer For Oxy-Coal Combustion, Nicole Ashley Burchfield Apr 2020

Narrow Angle Radiometer For Oxy-Coal Combustion, Nicole Ashley Burchfield

Theses and Dissertations

A new method of power production, called pressurized oxy-fuel combustion, burns coal with CO2 and oxygen, rather than air, bringing us closer to the end goal of developing zero emission coal-fired utility boilers. However, high-pressure, high-temperature systems such as these are under-studied, and their behavior is difficult to measure. An accurate model for previously untested conditions requires data for validation. The heat release profile of flames and their radiative intensity is one of the key data sets required for model validation of an oxy-coal combustion system. A radiometer can be used to obtain the necessary radiative heat flux data. However, …


Development Of A Parameterized Model Of Transverse Maize (Zea Maysl.) Stalk Morphology, Ryan A. Larson Apr 2020

Development Of A Parameterized Model Of Transverse Maize (Zea Maysl.) Stalk Morphology, Ryan A. Larson

Theses and Dissertations

Stalk lodging, or failure of the stalk structure, presents a serious problem in the production of maize (Zea mays L.). Lodged stalks negatively impact crop yields by inhibiting further grain growth and often prevent the harvest of the grain. Addressing this problem requires the development of new maize hybrids that exhibit enhanced lodging resistance, which in turn requires an understanding of the parameters that influence lodging resistance. Current methods make use of specimen-specific geometry and material properties, but these methods have limited ability to examine geometric effects and can require excessive time. A parameterized model of the maize stalk has …


Pitch And Thrust Allocation For Full-Flight-Regime Control Of Winged Evtol Uavs, Jacob B. Willis, Randal W. Beard Apr 2020

Pitch And Thrust Allocation For Full-Flight-Regime Control Of Winged Evtol Uavs, Jacob B. Willis, Randal W. Beard

Faculty Publications

Trajectory tracking control for winged eVTOL aircraft is complicated by the high-angle-of-attack aerodynamics experienced during navigational flight occurring immediately after takeoff and immediately before landing. The total energy use of the vehicle can be reduced and the control performance can be improved by appropriately considering the pitch angle of the vehicle in varying flight conditions. We present a review of high-angle-of-attack aerodynamic models as well as an algorithm for finding the optimal pitch and thrust of a winged eVTOL throughout its flight regime. We show simulation results demonstrating a 75% reduction in tracking error over our previous work while maintaining …


Space-Time Coding For The Advanced Range Telemetry Continuous Phase Modulation, Robert L. Leatham Apr 2020

Space-Time Coding For The Advanced Range Telemetry Continuous Phase Modulation, Robert L. Leatham

Theses and Dissertations

Aeronautical telemetry systems that transmit the same signal through multiple antennas from the flight vehicle suffer from severe link dropouts when the signals destructively interfere one with another at receiver. The underlying issue is a transmit array with element spacing far greater than the wavelength producing a transmit antenna pattern with significant and deep nulls. Recently, space-time coding techniques have been proven to resolve the issue for systems using linear modulations and shaped-offset quadrature shift keying (SOQPSK) modulation, a non-linear continuous phase modulation (CPM). This thesis examines application of space-time coding techniques to resolve the self-interference issue for another CPM …


An Open-Source Web-Application For Regional Analysis Of Grace Groundwater Data And Engaging Stakeholders In Groundwater Management, Travis Clinton Mcstraw Apr 2020

An Open-Source Web-Application For Regional Analysis Of Grace Groundwater Data And Engaging Stakeholders In Groundwater Management, Travis Clinton Mcstraw

Theses and Dissertations

Since 2002, NASA's GRACE Satellite mission has allowed scientists of various disciplines to analyze and map the changes in Earth's total water storage on a global scale. Although the raw data is available to the public, the process of viewing, manipulating, and analyzing the GRACE data can be difficult for those without strong technological backgrounds in programming or geospatial software. This is particularly true for water managers in developing countries, where GRACE data could be a valuable asset for sustainable water resource management. To address this problem, I have a developed a utility for subsetting GRACE data to particular regions …


Isogeometric Shell Analysis: Multi-Patch Coupling And Overcoming Locking, Zhihui Zou Apr 2020

Isogeometric Shell Analysis: Multi-Patch Coupling And Overcoming Locking, Zhihui Zou

Theses and Dissertations

The fundamental advantages of applying Isogeometric Analysis (IGA) to shell analysis have been extensively demonstrated across a wide range of problems and formulations. However, a phenomenon called numerical locking is still a major challenge in IGA shell analysis, which can lead to dramatically deteriorated analysis accuracy. Additionally, for complex thin-walled structures, a simple and robust coupling technique is desired to sew together models composed of multiple patches. This dissertation focuses on addressing these challenges of IGA shell analysis. First, an isogeometric dual mortar method is developed for multi-patch coupling. This method is based on Be ?zier extraction and projection and …


Ku-Band Ultra-High Resolution Radar Tomography Of An Alpine Snowpack, Ryan Natale Bartley Apr 2020

Ku-Band Ultra-High Resolution Radar Tomography Of An Alpine Snowpack, Ryan Natale Bartley

Theses and Dissertations

A commercial-off-the-shelf Ku-band Frequency Modulated Continuous Wave (FMCW) synthetic aperture radar (SAR) system is coupled with a custom built two-dimensional scanning system. This system is installed in an alpine environment and pointed at a snow-unstable mountain slope for the duration of a Utah winter. The radar scanning system, designed to be capable of mapping a snowpack and its layers, is employed to create a series of three-dimensional images from a remote location. Individual images demonstrate the ability to directly detect snow layers, Furthermore, successive images are compared to track volume magnitude and phase values over the course of winter, including …


Development Of A Simplified Performance-Based Procedure For Assessment Of Liquefaction Triggering For The Cone Penetration Test, Jenny Lee Blonquist Apr 2020

Development Of A Simplified Performance-Based Procedure For Assessment Of Liquefaction Triggering For The Cone Penetration Test, Jenny Lee Blonquist

Theses and Dissertations

Soil liquefaction can cause devastating damage and loss and is a serious concern in civil engineering practice. One method for evaluating liquefaction triggering potential is a risk-targeted probabilistic approach that has been shown to provide more consistent and accurate estimates of liquefaction risk than traditional methods. This approach is a “performance-based” procedure which is based off of the performance-based earthquake engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) Center. Unfortunately, due to its complexity, performance-based liquefaction assessment is not often used in engineering practice. However, previous researchers have developed a simplified performance-based procedure which incorporates the accuracy …


Benchmark Temperature Microcontroller For Process Dynamics And Control, Junho Park, Ronald Abraham Martin, Jeffrey Kelly, John Hedengren Apr 2020

Benchmark Temperature Microcontroller For Process Dynamics And Control, Junho Park, Ronald Abraham Martin, Jeffrey Kelly, John Hedengren

Faculty Publications

Standard benchmarks are important repositories to establish comparisons between competing model and control methods, especially when a new method is proposed. This paper presents details of an Arduino micro-controller temperature control lab as a benchmark for modeling and control methods. As opposed to simulation studies, a physical benchmark considers real process characteristics such as the requirement to meet a cycle time, discrete sampling intervals, communication overhead with the process, and model mismatch. An example case study of the benchmark is quantifying an optimization approach for a PID controller with 5.4% improved performance. A multivariate example shows the quantified performance improvement …


Characterization Of The Factors Influencing Retained Austenite Transformation In Q&P Steels, Derrik David Adams Apr 2020

Characterization Of The Factors Influencing Retained Austenite Transformation In Q&P Steels, Derrik David Adams

Theses and Dissertations

Formable Advanced High-Strength Steels (AHSS) have a unique combination of strength and ductility, making them ideal in the effort to lightweight vehicles. The AHSS in this study, Quenched and Partitioned 1180, rely on the Transformation Induced Plasticity (TRIP) effect, in which retained austenite (RA) grains transform to martensite during plastic deformation, providing extra ductility via the transformation event. Understanding the factors involved in RA transformation, such as local strain and grain attributes, is therefore key to optimizing the microstructure of these steels. This research seeks to increase understanding of those attributes and the correlations between microstructure and RA transformation in …


Three-Dimensional Hydrodynamic Focusing For Integrated Optofluidic Detection Enhancement, Erik Scott Hamilton Apr 2020

Three-Dimensional Hydrodynamic Focusing For Integrated Optofluidic Detection Enhancement, Erik Scott Hamilton

Theses and Dissertations

The rise of superbugs, including antibiotic-resistant bacteria, and virus outbreaks, such as the recent coronavirus scare, illustrate the need for rapid detection of disease pathogens. Widespread availability of rapid disease identification would facilitate outbreak prevention and specific treatment. The ARROW biosensor microchip can directly detect single molecules through fluorescence-based optofluidic interrogation. The nature of the microfluidic channels found on optofluidic sensor platforms sets some of the ultimate sensitivity and accuracy limits and can result in false negative test results. Yet higher sensitivity and specificity is desired through hydrodynamic focusing. Novel 3D hydrodynamic focusing designs were developed and implemented on the …


High-Speed And Low-Power Techniques For Successive-Approximation-Register Analog-To-Digital Converters, Eric Lee Swindlehurst Apr 2020

High-Speed And Low-Power Techniques For Successive-Approximation-Register Analog-To-Digital Converters, Eric Lee Swindlehurst

Theses and Dissertations

Broadband wireless communication systems demand power-efficient analog-to-digital converters (ADCs) in the GHz and medium resolution regime. While high-speed architectures such as the flash and pipelined ADCs are capable of GHz operations, their high-power consumption reduces their attractiveness for mobile applications. On the other hand, the successive-approximation-register (SAR) ADC has an excellent power efficiency, but its slow speed has traditionally limited it to MHz applications. This dissertation puts forth several novel techniques to significantly increase the speed and power efficiency of the SAR architecture and demonstrates them in a low-power 10-GHz SAR ADC suitable for broadband wireless communications. The proposed 8-bit, …


Bacteria In Blood: Optimized Recovery Of Bacterial Dna For Rapid Identification, Ryan Wood Mar 2020

Bacteria In Blood: Optimized Recovery Of Bacterial Dna For Rapid Identification, Ryan Wood

Theses and Dissertations

Blood stream infections are challenging infections to rapidly diagnose. The current clinical diagnostic methods for blood stream infections require culturing the blood sample prior to identifying the bacteria and any resistance the bacteria may contain. Removing the culturing step from the bacterial identification process of a blood stream infection provides a significant reduction in the processing time. However, eliminating the culturing step shifts the difficulty from processing time to concentration, since clinical concentration levels can be as low as 10 CFU/mL in blood. This dissertation developed and evaluated many aspects of the process required to identify bacteria from a blood …