Engineering Commons^™

Modulation And Long-Term Release Of Cardiac Fibroblast Secretome To Enhance Cardiac Cell Survival Under Hypoxia, Jingxuan Zhai

McKelvey School of Engineering Graduate Student Theses & Dissertations

The irreversible damage to the heart caused by myocardial infarction (MI) leads to over one million deaths in the United States every year. There are several approaches to treat MI, such as angioplasty, redirected blood flow, and electrical medical devices, but they cannot promote new cardiac tissue generation, thus leading to potential high risk of re-surgeries. To overcome this limitation, stem cell therapy is regarded as a promising method. However, the implantation of stem cells has ethical and safe concern and the efficiency is limited due to low cell engraftment. Moreover, the effect of stem cell is predominantly attributed to …

Design And Optimization Of An Array Of Hollow Micropillar Structures For Enhanced Evaporative Cooling, Zhikai Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the increasing demand for higher-performance chips, the architecture of these semiconductor devices becomes more complex, leading to the need for higher-performance cooling technologies. For example, 3D stacked chips offer several advantages, including mixed functionality, reduced signal delay, and a smaller footprint. However, these devices yield higher heat densities due to the heat compounded from one stacked die to the next. While traditional single-phase cooling technologies can dissipate large heat fluxes, its performance is inversely proportional to its hydraulic diameter leading to larger required pumping powers. Two-phase cooling is a promising technique for dissipating high heat fluxes by utilizing the …

Analyzing Speech Recognition For Individuals With Down Syndrome, Yingying 'Yuki' Chen, Franceli L. Cibrian, Deanna Hughes, Vivian Genaro Motti

Student Scholar Symposium Abstracts and Posters

With the increment of voice assistants, speech recognition technologies have been used to support natural language processing. However, there are limitations on how well the technologies perform depending on who the users are. They have been predominantly trained on “typical speech” patterns, leaving aside people with disabilities with unique speech patterns. More specifically, people with Down Syndrome are having trouble using speech recognition technology due to their differences in speech. To develop a more accessible voice assistant, this project aims to characterize the speech recognition from individuals with Down Syndrome. To accomplish this aim, we analyze the quality of transcripts …

Multi-Degree Of Freedom Position And Attitude Control Of Rings Dipoles Using Electromagnetic Forces And Torques, David Andres Alvarez

Theses and Dissertations

Satellite formation flight (SFF) is likely to transform and advance the scope of space missions in the near future. Some considerable benefits of SFF to a mission include robustness, adaptability, and potential cost savings. However, satellite formations face a fuel expenditure issue: the more spacecraft there are to control, the more fuel will be expended on alignment and maneuvering. A solution to this problem is Electromagnetic Formation Flight (EMFF), which is the application of conductive coils in producing electromagnetic fields that can interact with the fields of other coils in a formation to exchange forces and torques. With three orthogonal …

Robust And Scalable Data Representation And Analysis Leveraging Isometric Transformations And Sparsity, Alireza Zaeemzadeh

Electronic Theses and Dissertations, 2020-2023

The main focus of this doctoral thesis is to study the problem of robust and scalable data representation and analysis. The success of any machine learning and signal processing framework relies on how the data is represented and analyzed. Thus, in this work, we focus on three closely related problems: (i) supervised representation learning, (ii) unsupervised representation learning, and (iii) fault tolerant data analysis. For the first task, we put forward new theoretical results on why a certain family of neural networks can become extremely deep and how we can improve this scalability property in a mathematically sound manner. We …

Infants' Facial Emotion Recognition, Umme Fatema

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facial Emotion Recognition (FER) has become a popular computer vision topic and attracted a lot of researchers. However, these researches mostly focus on adult facial emotion. Infants’ facial structure and expression of emotions differ from adults’. That is why our target is to create a model that particularly focuses on infants’ facial emotions. In this work, we classify three types of emotions: positive, negative, and neutral. Two datasets are used in this work. One is an image-based dataset named ‘The City’ that consists of 154 images of infants aged 0-12 months. Another is the Rebel Dataset from the Department of …

Healthy Aging In Place: An Integrated Smart Home Using Alexa-Compatible Technology, Tyler Kryst

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to address current healthcare concerns among the aging population. Around the globe, the average life expectancy is projected to continue increasing resulting in a higher prevalence of age-related disease. With the ever-increasing capabilities of modern technology, it is necessary to apply this technology to increase the health and safety of older adults. This work had three objectives. The first objective was the establishment of an integrated smart home aimed at creating a healthy aging-in-place environment through the use of Alexa. The second objective was the development and integration of a completely custom health device …

Deep Convolutional Spiking Neural Networks For Image Classification, Ruthvik Vaila

Boise State University Theses and Dissertations

Spiking neural networks are biologically plausible counterparts of artificial neural networks. Artificial neural networks are usually trained with stochastic gradient descent (SGD) and spiking neural networks are trained with bioinspired spike timing dependent plasticity (STDP). Spiking networks could potentially help in reducing power usage owing to their binary activations. In this work, we use unsupervised STDP in the feature extraction layers of a neural network with instantaneous neurons to extract meaningful features. The extracted binary feature vectors are then classified using classification layers containing neurons with binary activations. Gradient descent (backpropagation) is used only on the output layer to perform …

Binary Particle Mixtures As A Heat Transfer Media In Shell-And-Plate Moving Packed Bed Heat Exchangers, Chase Ellsworth Christen

Boise State University Theses and Dissertations

Solid particles are being considered in several high temperature thermal energy storage systems and as heat transfer media in concentrated solar power (CSP) plants. The downside of such an approach is the low overall heat transfer coefficients in shell-and-plate moving packed bed heat exchangers caused by the inherently low packed bed thermal conductivity values of the low-cost solid media. Choosing the right particle size distribution of currently available solid media can make a substantial difference in packed bed thermal conductivity, and thus, a substantial difference in the overall heat transfer coefficient of shell-and-plate moving packed bed heat exchangers. Current research …

Millimeter-Wave Channel Measurement At 73ghz And 81ghz, Changyu Guo

Boise State University Theses and Dissertations

The abundant spectrum available at mmWave band can provide high capacity, high throughput, and low latency. In this thesis, we present experimental measurements for 73 and 81 GHz mmWave bands. Wideband propagation measurements were performed at the Boise Airport concourse C area and tarmac for both line-of-sight (LOS) and non-line-of sight (NLOS) scenarios. Power delay profiles were recorded and analyzed with close-in free space reference path loss models and floating intercept path loss models. In addition, building material attenuation at 28, 73, and 91 GHz is presented. Measurements at 73 GHz for wideband and narrowband signal are performed with directional …

A Low Cost Sensor System For Monitoring And Predicting Corrosion Of Long Term Spent Nuclear Fuel Storage, Vikram M. Patel

Boise State University Theses and Dissertations

With the closing of the Yucca mountain storage facility, on-site storage of spent nuclear fuel at reactor sites has increased and will continue to increase until a permanent storage facility is prepared. Dry storage canisters are used to store spent nuclear fuel waste over long periods of time, but are susceptible to mechanical failure via corrosion. This dissertation presents a system to monitor the integrity of the storage canister. Sensor data fusion algorithms have been designed to predict the integrity of the storage system and provide feedback for preventative maintenance. The environmental conditions that lead to corrosion have been replicated …

Design And Development Of Optical Waveguide Architectures For Real-Time Temperature Monitoring In Extreme Environments, Bahareh Badamchi

Boise State University Theses and Dissertations

This dissertation prompts on the research and development of a new real-time, reusable, and reversible optical sensor for integrated temperature monitoring in harsh environments. This is achieved through integrating the photonic properties of optical waveguides/optical fiber and the phase change properties of chalcogenide glasses (ChGs). ChG materials have very specific crystallization temperatures beyond which these materials transform from being a dielectric material to a metallic material. When such ChG material is coated over a dielectric optical waveguide, in the crystalline phase, highly localized surface plasmon polariton (SPP) modes are generated at the waveguide: metallic ChG interface. In this case, the …

First-Principles Studies Of Nucleation Of Atomic-Layered Molybdenum Disulfide By Atomic Layer Deposition, Matthew Lawson

Boise State University Theses and Dissertations

This dissertation implements first-principles calculations to understand the nucleation mechanisms for atomic layer deposition (ALD) of molybdenum disulfide (MoS₂) using MoF₆ and H₂S precursors. ALD is a self-limiting process that can deposit a range of materials at the nanoscale, while maintaining chemical stoichiometry, atomic scale thickness control, and can conform to high-aspect ratio substrate designs. ALD is extremely sensitive to surface chemistry and morphology; therefore, it is critical to understand how these factors control deposition.

Density functional theory (DFT) was used to understand what factors can control the nucleation for ALD of MoS₂ using …

Tensile-Strained Germanium Quantum Dots Grown On Indium Aluminum Arsenide (111)A And (110) By Molecular Beam Epitaxy, Kathryn Eva Sautter

Boise State University Theses and Dissertations

Molecular beam epitaxy (MBE) enables the growth of semiconductor nanostructures known as tensile-strained quantum dots (TSQDs). The highly tunable nature of TSQD properties means that they are of interest for a wide variety of applications including for infrared (IR) lasers and light-emitting diodes (LEDs), improved tunnel junction efficiency in multijunction solar cell technology, quantum key encryption, and entangled photon emission. In this project, I focus on one of the most technologically important materials, germanium (Ge). Ge has a high gain coefficient, high electron mobility, and low band gap: all excellent properties for optoelectronic applications. Until recently, these technological advantages were …

3d Printable And Computational Models Of The Bone Marrow Mechanical Environment, Alexander Regner

Boise State University Theses and Dissertations

Aged individuals and astronauts experience bone loss despite rigorous physical activity. Bone mechanoresponse is in part regulated by mesenchymal stem cells (MSCs). We reported that daily low intensity vibration (LIV) restores MSC proliferation in senescence and simulated microgravity models, suggesting reduced mechanical signal delivery to MSCs likely contributes to declining bone mechanoresponse. To this end, we have developed a 3D bone marrow analog which controls trabecular geometry, marrow mechanics and external stimuli.

Finite element (FE) models of hydrogels, representing bone marrow, were generated using instantaneous compression (1000% strain/s, 20% strain) and relaxation experiments (100s) of both gelatin and hyaluronin-based hydrogels. …

Sustainable Agricultural Development In The Western Desert Of Egypt Under Climate Change: A Case Study Of The Siwa Region, Noha Hossam Moghazy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Siwa region located in the Western Desert of Egypt is a natural depression and has a large volume of groundwater from the non-renewable Nubian Sandstone Aquifer System (NSAS). Recently the government initiated a development project to reclaim 1.5 million acres where most of the lands are located in the Western Desert to use available groundwater from NSAS. The primary goal of this project is to increase agricultural areas enabling rural development. Siwa is one of the areas that will be reclaimed in the desert by about 30,000 acres consisting of good soil quality. This dissertation aims to understand the …

Three-Phase Unfolding Based Soft Dc-Link Converter Topologies For Ac To Dc Applications, Dorai Babu Yelaverthi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Battery electric vehicles (BEVs) and plugin hybrid electric vehicles (PHEVs) are more efficient than internal combustion-based vehicles. Adaption of EVs will help reduce the carbon emissions produced by the transportation sector. The charging infrastructure has to grow at a rapid pace to encourage EV adaption. Installing higher capacity fast chargers will help alleviate the range anxiety of battery electric vehicle customers. More public charging stations are required for the full adaption of EVs. Utility power is distributed as ‘alternating current.’ A battery requires ‘direct current’ (DC) source to charge it. Hence a power converter that converts AC source to DC …

Computational Fluid Dynamics Benchmark Validation Experiment Of Plenum-To-Plenum Flow Through Vertical Heated Parallel Channels, Austin W. Parker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The next generation of nuclear power plants will have higher efficiency and improved safety, among other benefits; one attractive option is the high temperature gas reactor. An ability to predict the physics that occur within the reactor under normal conditions and accident scenarios is necessary before it receives regulatory licensing for use. The flow through a high temperature gas reactor involves complex interactions of heat transfer, fluids, and solids.

One method for simulating complex fluid dynamics is called Computational Fluid Dynamics. These simulations have already been used to predict the complex fluid flows found in high temperature gas reactors. Predicting …

Effects Of Climate Forcing Uncertainty On High-Resolution Snow Modeling And Streamflow Prediction In A Mountainous Karst Watershed, Conor Tyson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Snow-dominated, karst watersheds present particular challenges to accurately modeling streamflow in response to differing climate conditions. This is due to the uneven distribution of snow within a basin, the varied melting rates due to terrain and climate, and the difficulty determining flow paths through karst conduits below ground. One possible solution to these challenges is to model snow at a fine scale, but climate variables are not available at these smaller spatial scales. The choices about which climate dataset to use, and how to downscale the data to a fine scale, will likely affect the accuracy of streamflow simulations. This …

Sensitivity And Estimation Of Aerodynamic, Propulsion, And Inertial Parameters For Rudderless Aircraft Using Simulation, Jaden W. Thurgood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique known as system identification is often used in aircraft design and testing to understand and validate the mathematical parameters that describe the aircrafts stability and handling characteristics. System identification can be thought of as the inverse of simulation. In the world of system identification, we have a physical system that we seek to understand in more detail by monitoring the system with an array of sensors. In short, we conduct tests of an aircraft while recording the inputs and response outputs. Then we take the input and output data and run it through an algorithm that seeks to …

Uses And Challenges Of Collecting Lidar Data From A Growing Autonomous Vehicle Fleet: Implications For Infrastructure Planning And Inspection Practices, Md Ashikur Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Autonomous vehicles (AVs) that utilize LiDAR (Light Detection and Ranging) and other sensing technologies are becoming an inevitable part of transportation industry. Concurrently, transportation agencies are increasingly challenged with the management and tracking of large-scale highway asset inventory. LiDAR has become popular among transportation agencies for highway asset management given its advantage over traditional surveying methods. The affordability of LiDAR technology is increasing day by day. Given this, there will be substantial challenges and opportunities for the utilization of big data resulting from the growth of AVs with LiDAR. A proper understanding of the data size generated from this technology …

Biomethanation And Alkaline Wet Air Oxidation Of Water Hyacinth (Pontederia Crassipes) From Ozama River, Dominican Republic, Yessica A. Castro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Obtaining valuable products from environmental remediation waste is a sustainable approach that contributes to the ecological well-being of developing countries. In the present work, the feasibility of the water hyacinth anaerobic digestion as a post-weed management practice in the Ozama River (Dominican Republic) was demonstrated. The estimated energy required for harvesting was lower than that produced during digestion. The biomethanation of water hyacinth was improved by Alkaline Wet Air Oxidation (AWAO), a thermochemical pretreatment process that almost doubled the methane production rate and increased the yield by 24% when conducted at high temperatures. At lower temperatures, the methane yield of …

Application Of Flow And Ion Data To Estimate Ungaged Inflows And Losses In Urban And Agricultural Sub-Reaches Of The Logan River Observatory, Hyrum Tennant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Streams in urban and agricultural environments are often heavily diverted for irrigation and drinking water purposes. These streams can receive inflow from unmeasured sources including stormwater returns, groundwater drains, and irrigation runoff that will help sustain flow during dry periods. Due to an inability to identify the source of most of these inflows or directly measure their volumes, there is a clear need for identification and quantification methods. Streamflow data from the Logan River Observatory illustrates the importance of unidentified inflows in sections influenced by large diversions. To understand the role of unidentified inflows and possible outflows in this portion …

Raw Depth Image Enhancement Using A Neural Network, Xuan Xie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The term image is often used to denote a data format that records information about a scene’s color. This dissertation object focuses on a similar format for recording distance information about a scene, “depth images”. Depth images have been used extensively in consumer-level applications, such as Apple’s Face ID, based on depth images for face recognition.

However, depth images suffer from low precision and high errors, and some post-processing techniques need to be utilized to improve their quality. Deep learning, or neural networks, are frameworks that use a series of hierarchically arranged nonlinear networks to process input data. Although each …

Accounting For Critical Attributes And Uncertainty In Flow-Ecology Relationships, Elizabeth Decker Morgan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Environmental flows are used to maintain streamflow for aquatic species in rivers while also sustaining human water requirements. While there are many approaches to develop environmental flows, they all rely on a strong conceptual understanding of flow-ecology relationships, which are often uncertain. Uncertainty in flow-ecology relationships can stem from using limited data to develop or test relationships or an incomplete understanding of the attributes inherent to each relationship, such as climate and land conditions. Accounting for these attributes and uncertainty in flow-ecology relationships is critical given mounting interest to develop and implement environmental flows at large scales, often with limited …

Design Of Miniaturized Sweeping Langmuir Probe And Electric Field Probe For The Sport Mission, Nathan P. Tipton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Scintillation Prediction Observation Research Task (SPORT) is a joint United States of America and Brazil 6U CubeSat mission. The US is providing the science instruments and the spacecraft launch. Brazil is providing the spacecraft bus, integration, and operations. Utah State University will provide four instruments for the mission as part of the US contribution in a suite called the Space Weather Probes (SWP). These instruments are the Sweeping Langmuir Probe (SLP), the Electric Field Probe (EFP), and the Sweeping Impedance Probe (SIP). Higher frequency components of the SLP and EFP will be observed through a Wave Spectrometer (WS). These …

Application Of Computational Fluid Dynamics To Determine Gas Expansion Factors Of Differential Pressure Flow Meters, Patrick L. Campana

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate if computer simulations could be used to accurately predict gas expansion in differential pressure flow meters. Differential pressure flow meters are used to measure the flow rate of pressurized liquids and gases through pipes. Computer simulations of liquid and gas flows were conducted for three distinct differential pressure flow meter geometries: Classical Venturis, Stand Concentric orifice plates, and wedge meters.

Gas flows were modeled as dry air using the assumption of a perfect gas. Expansion effects were modeled using the ideal gas law. Computer simulations of Classical Venturi and Standard Concentric orifice …

A Laboratory Study On The Geometric Effects Of Piano Key Weirs On Scour For Non-Cohesive Substrates And Simple Mitigation Techniques, Wyatt Lantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sustainable flood control infrastructure is needed as climate change continues to produce more extreme precipitation events, as our water infrastructure continues to age, and as populations continue to grow and expand. Non-linear weirs, such as labyrinth and piano key weirs, are sustainable passive flood-control structures due to their improved hydraulic performance, and low maintenance and construction costs. However, like other structures, these weirs are susceptible to local scour, which is removal of soil and rock due to hydraulic forces. The scour phenomenon is a complicated process dependent upon multiple variables. There is limited information for non-linear weirs with little directed …

A Laboratory Study Of The Hydraulics Of Moderate-Sloped Stepped Chutes With A Labyrinth Crest, L. Kade Flake

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Evolving methods of dam construction and rehabilitation require unique and innovative spillways. Spillways provide passage for water impounded by a dam. Stepped chute spillways offer an efficient and economical solution for dam construction and rehabilitation. Labyrinth weirs, which allow high flow discharge within a compact footprint, are often an economical solution for the spillway crest at a chute entrance. Labyrinth weirs have recently been combined with stepped chutes in several locations. However, published literature is scarce for the flow properties and key design parameters of these combined structures.

This study researched the hydraulics downstream of a labyrinth crest for two …

Numerical Simulation Of Losses In Four-Way Pipe Junctions, Simon Barth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To design pipelines, engineers need to know how much energy the fluid in the pipe has at different locations in the pipe network. The energy the fluid has comes in the form of pressure, velocity, and elevation. As fluid travels through a pipe, it loses energy for many different reasons. Some of those reasons include friction between the fluid and the pipe wall, shear forces within the fluid, changes in flow direction, changes in elevation, or various pipe fittings like elbows, tee’s, valves, reducers, and expanders. Many of the causes of energy loss are well researched. One cause of energy …