Engineering Commons^™

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 …

Design And Characterization Of A Triple-Input Microfluidic Droplet Trapping Array Towards Multiplexed And Dynamic Single Cell Analysis, Riad Elkhanoufi

Honors Capstones

No abstract provided.

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 …

Building A Smart Nation: Singapore's Digital Journey, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

Singapore’s smart nation journey began when the drive was officially announced by the country’s Prime Minister Lee Hsien Loong in November 2014 (Lee, 2014). The vision is to improve people’s lives and create more opportunities through information and communications technology (ICT). The smart nation drive is an effort by the government to co-create innovative, people-centric solutions with citizens and businesses. The three priority areas, underpinned by cyber security, are elderly, transportation and data. Since then, various digital strategies and policies have been further articulated, and digital programmes and projects implemented in the country.

Budget-Constrained Regression Model Selection Using Mixed Integer Nonlinear Programming, Jingying Zhang

Graduate Theses and Dissertations

Regression analysis fits predictive models to data on a response variable and corresponding values for a set of explanatory variables. Often data on the explanatory variables come at a cost from commercial databases, so the available budget may limit which ones are used in the final model.

In this dissertation, two budget-constrained regression models are proposed for continuous and categorical variables respectively using Mixed Integer Nonlinear Programming (MINLP) to choose the explanatory variables to be included in solutions. First, we propose a budget-constrained linear regression model for continuous response variables. Properties such as solvability and global optimality of the proposed …

Growth And Characterization Of Silicon-Germanium-Tin Semiconductors For Future Nanophotonics Devices, Bader Saad Alharthi

Graduate Theses and Dissertations

The bright future of silicon (Si) photonics has attracted research interest worldwide. The ultimate goal of this growing field is to develop a group IV based Si foundries that integrate Si-photonics with the current complementary metal–oxide–semiconductor (CMOS) on a single chip for mid-infrared optoelectronics and high speed devices. Even though group IV was used in light detection, such as photoconductors, it is still cannot compete with III-V semiconductors for light generation. This is because most of the group IV elements, such as Si and germanium (Ge), are indirect bandgap materials. Nevertheless, Ge and Si attracted industry attention because they are …

Experimentation And Modeling Of The Effects Of Along-Wind Dispersion On Cloud Characteristics Of Finite-Duration Contaminant Releases In The Atmosphere, Jessica M. Morris

Graduate Theses and Dissertations

Along-wind dispersion, or stretching of the cloud in the direction of the wind, plays an important role in the concentration and modeling of contaminant releases in the atmosphere. Theoretical and empirical derivations were compared for appropriate parameterization of along-wind dispersion. Available field data were analyzed to evaluate and improve previous parameterizations of the along-wind dispersion coefficient, σ_x. An experimental test program was developed and executed in an ultra-low speed wind tunnel at the Chemical Hazards Research Center to determine the effects of the time distribution coefficient on true finite-duration releases from an original area source. Multiple wind speeds, release durations, …

Measuring Characteristic Shrinkage Variability Due To Metal Loading Effects In Low Temperature Co-Fired Ceramic Using Image Processing, John Ezekiel Zumbro

Graduate Theses and Dissertations

Low temperature co-fired ceramic (LTCC) has many benefits when it comes to electronic packaging due to the low dielectric loss, reliability in extreme environments, and high breakdown voltage. Though the ceramic has a lot of benefits it is not widely used due to the high cost and complexities associated with manufacturing. One of these issues with manufacturing is compensating for the shrinkage of the ceramic, this is accomplished by using an expansion factor, creating the “green” or manufactured design. This expansion factor is approximated through knowledge of the ceramic factors such as the metal loading, layers of ceramic tape, firing …

Experimental Investigation Of A Green Hybrid Thruster Using A Moderately Enriched Compressed Air As The Oxidizer, Marc Anthony Bulcher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A hybrid rocket is a propulsion system that uses propellants in two different phases, typically a solid fuel inside the combustion chamber and a separate gaseous or liquid oxidizer stored in a tank. Hybrid rockets are an area of research interest because of their low explosive risk, inexpensive components, and high degree of reliability. In the Propulsion Research Laboratory at Utah State University, pure oxygen is among the top choice for hybrid rocket oxidizers due to its low cost and ease of storage. When paired with a solid fuel known as ABS (acrylonitrile butadiene styrene) plastic, specific impulse values exceed …

Autonomous Trajectory Planning For Satellite Rpo And Safety Of Flight Using Convex Optimization, Nicholas G. Ortolano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Optimal trajectory planning methods that implement convex optimization techniques are applied to the area of satellite rendezvous and proximity operations. This involves the development of linearized relative orbital motion dynamics and constraints for two satellites, where one maintains a near-circular reference orbit. The result is formulated as a convex optimization problem, where the objective is to minimize the amount of fuel required to transfer from a given initial condition to the desired final conditions. A traditional rendezvous and proximity operations scenario is analyzed, which includes examples of initial approach, inspection, final approach, and docking trajectories. This scenario may include trajectory …

Non-Contact Evaluation Methods For Infrastructure Condition Assessment, Sattar Dorafshan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States infrastructure, e.g. roads and bridges, are in a critical condition. Inspection, monitoring, and maintenance of these infrastructure in the traditional manner can be expensive, dangerous, time-consuming, and tied to human judgment (the inspector). Non-contact methods can help overcoming these challenges. In this dissertation two aspects of non-contact methods are explored: inspections using unmanned aerial systems (UASs), and conditions assessment using image processing and machine learning techniques. This presents a set of investigations to determine a guideline for remote autonomous bridge inspections.

Supporting Adolescent Metacognition In Engineering Design Through Scripted Prompts From Peer Tutors: A Comparative Case Study, Kristin Marie Strong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 2013, developers of the Next Generation Science Standards implemented national K-12 directives and elevated engineering design to the level of scientific inquiry. Teaching design, however, is challenging to educators due to the complex nature of design problems, which cannot be solved via simple algorithms. Solving design problems requires a more reflective and iterative approach that emphasizes metacognitive skills like planning, monitoring, and taking another person’s perspective. Educators are further challenged by children’s immature metacognitive skills, which may be insufficient to engage in the entire design process.

A qualitative study of paired seventh graders demonstrated a pragmatic learning activity for …

Sparse Signal Recovery Based On Compressive Sensing And Exploration Using Multiple Mobile Sensors, Mohammad Shekaramiz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work in this dissertation is focused on two areas within the general discipline of statistical signal processing. First, several new algorithms are developed and exhaustively tested for solving the inverse problem of compressive sensing (CS). CS is a recently developed sub-sampling technique for signal acquisition and reconstruction which is more efficient than the traditional Nyquist sampling method. It provides the possibility of compressed data acquisition approaches to directly acquire just the important information of the signal of interest. Many natural signals are sparse or compressible in some domain such as pixel domain of images, time, frequency and so forth. …

Development Of An Improved Low-Order Model For Propeller-Wing Interactions, Joshua Taylor Goates

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For aircraft that have propellers mounted in front of the wings or tail, the prop wash produced by the propellers can have a strong influence on the aerodynamics of the aircraft. As the accelerated air from the propeller flows over the wings and tail, it can cause an alteration in the aerodynamic forces produced by those surfaces. Thus, an understanding of propeller-wing interactions is essential for the design and analysis of many aircraft.

There are multiple existing methods for analyzing the propeller-wing interactions. High order methods, such as wind tunnel testing or computational fluid dynamics, provide very accurate results but …

Spatial Ability Degradation In Undergraduate Mechanical Engineering Students During The Winter Semester Break, Benjamin J. Call

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spatial ability represents our ability to mentally arrange, rotate, and explore objects in multiple dimensions. This ability has been found to be important for engineers and engineering students. Past research has shown that many interventions can be created to boost an individual’s spatial ability. In fact, past research has indicated that engineering students significantly increase in spatial ability without an intervention while they are enrolled in certain engineering courses. Some researchers have claimed that the spatial ability boosts are permanent after an intervention. However, most researchers do not check the validity of that claim with continued assessment after more than …

Identification And Engineering Of Nonribosomal Peptide Biosynthetic Systems, Fuchao Xu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research focuses on the understanding and engineering of nonribosomal peptide biosynthetic pathways in Streptomyces coelicolor CH999, Escherichia coli BAP1 and Saccharomyces cerevisiae BJ5464-NpgA. The biosynthetic systems of indigoidine from bacteria and beauvericin/bassianolide from fungi were studied in this research. The production of these valuble products was significantly increased by enhancing their synthetic pathway with metabolic engineering approaches.

Indigoidine is a bacterial natural product with antioxidant and antimicrobial activities. Its bright blue color resembles the industrial dye indigo, thus representing a new natural blue dye that may find uses in industry. Indigo is a dark blue crystalline powder and has …

Droplet Impact Onto Super-Hydrophobic Surfaces And Determining The Response To Heat And Light Of Terrestrial Cyanobacteria, Benjamin B. Lovett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examines droplets striking water repelling surfaces as well as the movement of a soil based bacteria under various light and heat conditions. Droplet impact studies have shown that introducing a macroscopic feature to a water repelling surface can reduce the amount of time that droplet is in contact with the surface. By manipulating water droplets to impact different sized needles at varying speeds, we present how a needle can induce a similar reduction in the residence time of the droplet to more widely studied features. Results show the spreading and lift-off characteristics of the droplet are dependent on …

Application Of Winslamm To Evaluate The Effect Of Green Infrastructure Implementation In Northern Utah, Rosa A. Fernández Velásquez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study provides an evaluation of the performance of the WinSLAMM model in two cities of northern Utah, a region in which it has not been validated to date. Runoff volumes for a series of events from 2015 to 2017 were calculated for six study areas. These results were compared to model outputs to evaluate the prediction accuracy. The model performed poorly when default parameters where used, as expected. Thus, the calibration of runoff coefficient was done with local data. Total suspended solids (TSS), total phosphorus (TP) and total dissolved phosphorus (TDP) were also evaluated and calibrations were developed. The …

Automated Quantification And Evaluation Of Motion Artifact On Coronary Ct Angiography Images, Hongfeng Ma, Eric Gros, Scott G. Baginski, Zachary R. Laste, Naveen M. Kulkarni, Darin Okerlund, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Abstract

Purpose

This study developed and validated a Motion Artifact Quantification algorithm to automatically quantify the severity of motion artifacts on coronary computed tomography angiography (CCTA) images. The algorithm was then used to develop a Motion IQ Decision method to automatically identify whether a CCTA dataset is of sufficient diagnostic image quality or requires further correction.

Method

The developed Motion Artifact Quantification algorithm includes steps to identify the right coronary artery (RCA) regions of interest (ROIs), segment vessel and shading artifacts, and to calculate the motion artifact score (MAS) metric. The segmentation algorithms were verified against ground‐truth manual segmentations. The …

Flight Vehicle Design, Andrew Ning

Books

No abstract provided.

Evaluation Of Bond Properties Between Fiber Reinforced Concrete Overlay And Substrate Concrete, Emad Okrush Alshammari

Theses and Dissertations

Bonded concrete overlay is the most economical and quick option in concrete rehabilitation methods to provide strength for the existing structure. Bonded concrete overlay strength rely on properties of both layers (substrate and new layers). Poor bonding in interface zone leads to two main failures of concrete overlays; debonding and cracks. There are several traditional factors affect bond strength such as water to cement (w/c) ratio, moisture condition, and surface roughness for substrate layer. However, the effect of using fiber consider a new variable affecting bond strength. Fiber reinforced concrete (FRC) is one type of overlay system which has been …

Exploratory Analysis Of Accuracy Monitoring Techniques In Vehicle Detection Systems For Intelligent Transportation Systems Applications And Maintenance, Manasi Sanjay Palod

Theses and Dissertations

The goal of transportation management is to ensure the mobility of people and goods, in a reliable and efficient manner. Operation and maintenance of transportation infrastructure is key to accomplish their objectives. Intelligent Transportation Systems (ITS) applications rely on massive detection networks that collectively demand significant maintenance resources. Resource constraints force transportation agencies to look for innovative ways to optimize their operational and maintenance costs while serving their users at intended performance levels. The system inputs come from vehicle detection system (VDS), acting as field data collection devices, enabling traffic monitoring and management through response to specific conditions. This research …

Quantitative Measurement Techniques For Vibration And Buffet, Edward Thomas Meyer

Theses and Dissertations

This paper outlines a proposed parameter for measurement of vibration and buffet in vehicles. It is intended to be used where applicable in lieu of raw accelerometer data or qualitative comments to measure ride quality, quantify vibration levels, and aid in certification matters. In flight vehicle applications which employ fly-by wire flight control systems with closed loop and variable gain control laws, the phenomenon of buffet in its various forms is becoming somewhat specious as an aircrew cue in relation to the stability and control of flight vehicles. In these applications, stability and control throughout the operating envelope is designed …

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 …

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 …

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 …

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 …

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 …

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, …

Effect Of Film Cooling Hole Size On A Turbine Rotor Blade, Klint Martis

Theses and Dissertations

The objective of this study was to evaluate the effect of the cooling hole size on the adiabatic film cooling effectiveness over a rotating turbine blade section. The study was conducted using ANSYS FLUENT to determine the adiabatic wall temperature over the blade surface. The geometry was created to be a single section of a turbine rotating at 4000 rpm, and the blade increases in camber from tip to hub. Cylindrical cooling holes were created and the diameters were varied from 0.5 mm to 1.5 mm. The pitch-to-diameter ratio and the length-to-diameter ratio were kept constant at a value of …