Engineering Commons^™

Application Of Neural Networks For Solving One Dimensional Inverse Heat Conduction Problems With Surface Ablation, Jian Zhang

Theses and Dissertations

Thermal protection systems (TPS) are critical for space vehicles to keep them safe against extensive aerothermal heating, particularly during the atmospheric entry. Ablative materials burn away gradually when subjected to extreme heat flux and therefore are considered as a practical option for TPS application. Measurement of TPS surface condition, particularly heat flux, is essential to reduce design margins and also improve active control strategies for damage avoidance. However, it is not possible to directly measure TPS surface heat flux, and alternative approaches must be utilized for this purpose. One method is to use temperature sensors at internal layers and solve …

Development Of A Graphical User Interface For Ecg Signals Classification Using Statistical Features Analysis, Mousa Hammad S Aldosari

Theses and Dissertations

Cardiac diseases are the most common cause of mortality in the world. The detection of cardiac arrhythmias is not a straightforward process, since minor variations in the electrocardiogram (ECG) signals cannot be easily identified manually. Therefore, automatic detection and classification of cardiac arrhythmia would shorten the diagnostic time and accelerate medical intervention resulting in reducing the mortality rate. In this thesis, I have developed a simple and low-cost computer-aided diagnostic system using MATLAB-based Graphical User Interface (GUI) to facilitate fast operation and access to the data along with the overall accuracy of the system. The acquired ECG signals are processed …

Mechanical And Material Properties Of Nitinol And Its Application To Stents, Ariana Solis Eichler

Theses and Dissertations

Nitinol is a functional material with superelastic and shape memory properties derived from its unique molecular structure. The purpose of this thesis is to explore how the material and mechanical properties of self-expanding Nitinol stents affects the forces applied to arterial walls during stent deployment compared to the traditional balloon-expanding stainless steel stents, in addition to contrasting thin and thick-walled pressure vessel mathematical models. Nitinol’s mechanical properties can be optimized for stent applications by tailoring its processing procedures. Nitinol stents demonstrated a reduced circumferential hoop stress on the vessel wall and greater factor of safety with respect to vessel rupture …

An Experimental And Computational Mechanical Analysis Of Bone Anchors And Substrate Interface, Samantha May Schultz

Theses and Dissertations

Screw loosening is a common concern in orthopedic surgery. Therefore, this study is a computational and experimental evaluation of bone substrate and cortical screw interface. An axial load test was performed in an Instron with titanium alloy screws with 2.7 mm, 3.5 mm, and 4.5mm diameter orthopedic cortical screws inserted into SawBone with densities varying from 10 to 50 pounds per cubic foot (PCF), incrementing in sets of 10 PCF. SawBone was chosen in place of human bone because it has been shown to emulate the same mechanical properties (1). Twelve samples were prepared for each screw size and substrate …

Performance Analysis Of V2v And V2i Communications Using Empirical Path Loss Models Indicators And Embedded Iot Devices, Ibrahim Lateef Oraibi Al Kinoon

Theses and Dissertations

Vehicle management technologies deals with the management of critical vehicle information, including location, idle time, speed, and mileage. Such information can always be transferred through a direct vehicle-to-vehicle communication among cars. However, the limitation of this type of design is that it is based on the assumption that vehicles are always served by cellular bases, which is not always the case. For the effective implementation of the Internet-of-Things (IoT) technology in this sector, it is critical to design vehicles with systems that enable them to transmit essential information in the absence of base stations. IoT technologies can then be used …

Application Of Classification In Machine Learning: An Analysis Of Highway-Rail Grade Crossing Systems Safety, Christopher John Helmer Cox

Theses and Dissertations

Highway-rail grade crossing accidents are the second leading cause of fatalities within the railway transportation industry. Highway-rail grade crossing fatality statistics have failed to improve over the last decade, and in some years have increased. Because of these trends, research has found that considerable Federal funding initiatives exist to support and develop contemporary risk reduction methodologies involving machine learning and artificial intelligence. In accord with these initiatives, this thesis investigates the highway-rail grade crossing safety problem using machine learning to implement an ensemble decision tree-based classification application. The resulting classifier has been validated to achieve a less than three percent …

Computational Method To Calculate Output Current For Gated Spad To Determine Dcr And Pde, Ahmad Salih Azzahrani

Theses and Dissertations

The problem of detecting a single-photon is receiving considerable attention with the development of new single-photon detectors in stressed free-space optical communication, low probability of intercept (LPI) optical communication, quantum communication, and remote sensing. The theoretical modeling of the waveforms of the single-photon detector output produced in particular systems will expedite the search for and analysis of detected signals. A mathematical model of the output current of a single-photon avalanche detector (SPAD) gated with sinusoidal and Gaussian signals is developed and discussed. The mathematical model is combined with existing circuit and physical models to produce a compact model of the …

One Dimensional Neural Time Series Generation, Kaleb Earl Smith

Theses and Dissertations

Time dependent data is a main source of information in today’s data driven world.Generating this type of data though has shown its challenges and made it an interesting research area in the field of generative machine learning. The challenge with this one-dimensional (1D) data has been for applications in machine learning to gain access to a considerable amount of quality data needed for algorithm development and analysis. Modeling synthetic data using a Generative Adversarial Network (GAN) has been at the heart of providing a viable solution. Our work focuses on one dimensional times series and explores the “few shot” generation …

Graphene Surface Plasmon Applications In Designing Novel Nano-Heterostructure Arrays, Seyededriss Mirniaharikandi

Theses and Dissertations

Graphene is the flat monolayer of carbon atoms constructing a two-dimensional honeycomb lattice with an exotic mechanic, electronic, magnetic, and optical properties. Interestingly, the graphene has been experimentally shown its unique properties in photonics, where the first commercial application of graphene has been realized. Graphene possesses intrinsic plasmons that are electronically tunable, adjustable, and have low dissipation. Recently, the combination of graphene with noble metals and semiconductors structures promises a variety of exciting applications for conventional plasmonics and photonics. In this thesis, we present how to efficiently design heterostructure by combining graphene plasmonic metasurface with noble metals and semiconductors. First, …

A Feature-Based Approach To Function Modeling And Reasoning For Thermal-Fluid Systems Engineering, Lakshmi Narasimhon Athinarayana Venkatanarasimhan

Theses and Dissertations

This research is focused on extending the language of function modeling by developing CAD-like features that are built using primitive functions. These features are reusable units of functions that represent the working principle of a system of higher level of abstraction than the ones of the primitive functions published in prior literature. This approach can be used to also establish an alternate concept/working principle that satisfies the same features, and thus enabling the integration of function models into previously established concept generation programs. It is expected that designers perceive concepts at different levels of abstractions. As a result, the feature-based …

Investigating The Use Of 3d Printing Pens For Additive Manufacturing Component Repair, Kyle Andrew Koren

Theses and Dissertations

The work presented in this thesis provides fundamental research for investigating the application of 3D printing pens for the repair of components manufactured by 3D printers. Test specimens of three different print orientations were 3D printed with acrylonitrile-butadiene-styrene (ABS) and underwent a tensile load test, through rupture, to determine the maximum tensile load experienced. These ruptured specimens were then manually repaired with a 3D printing pen and put through another tensile test to determine the percentage of maximum tensile load retained. The two print orientations that had the axis of tensile load applied parallel to their print layers experienced rupture …

Alternative Material Selection For Oyster Restoration With An Emphasis On Living Docks, Bridgette Soucy

Theses and Dissertations

Oyster restoration efforts, including Living Shoreline and Living Dock projects, utilize aquaculture-grade plastic oyster mats to mitigate the decline of benthic communities. Aquaculture-grade plastic are known for strength, durability, and resilience to degradation in seawater. Over time, plastics break into microscopic segments commonly referred to as microplastics. Microplastics represent a major concern as marine organisms mistake the small particles for food. Plastics bioaccumulate in marine species, which impacts the marine food web and humans. In order to reduce further negative anthropogenic impacts, natural fibers and nature-inspired concrete mixtures were utilized across a series of experiments in order to determine an …

Analysis And Computation Of Polaritonic Systems In Infrared Regime For Sensing Applications, Abdelgader Ahmed Alshiekh Alsalhin

Theses and Dissertations

Generally, the aims of this work tend to focus on introducing novel designs for IR-sensing and a solid related knowledge based on computational analysis and investigations for polaritonic systems. This modern field of nanophotonics has been interested and promising nowadays thanks to the development in nano-fabrications and computing power and speed. Therefore, the theme-work is organized into two main parts along with the goals were addressed initially. The first part provides the necessary concepts for different responses of materials exposed to electromagnetic (EM) intensity which usually known as EM-matter interaction. Also, this part highlights how engineering these interactions in nano-scale …

Jet Impingement Heat Transfer From Superheated, Superhydrophobic Surfaces, David Jacob Butterfield

Theses and Dissertations

Liquid jet impingement is a technique ubiquitously used to rapidly remove large amounts of heat from a surface. Several different regions of heat transfer spanning from forced convection to nucleate, transition, and film boiling can occur very near to one other both temporally and spatially in quenching or high wall heat flux scenarios. Heat transfer involving jet impingement has previously shown dependency both on jet characteristics such as flow rate and temperature as well as surface material properties. Water droplets are known to bead up upon contact with superhydrophobic (SH) surfaces. This is due to reduced surface attraction caused by …

Use Of Viologens In Mediated Glucose Fuel Cells And In Aqueous Redox Flow Batteries To Improve Performance, Meisam Bahari

Theses and Dissertations

This dissertation presents my efforts to use viologens to improve the performance of glucose fuel cells and aqueous redox flow batteries. These two electrochemical systems have the potential to efficiently exploit renewable sources of energy. The contributions and significance of this work are briefly described below. Glucose Fuel cells. For glucose fuel cells, viologens were adopted as an electron mediator to facilitate the transfer of electrons from glucose to electrodes for power generation. Use of a mediator circumvents the need for precious metal electrodes to catalyze glucose oxidation. Both the oxidation efficiency and rate of glucose oxidation are important to …

Two Techniques For Automated Logging Statement Evolution, Allan R. Spektor

Theses and Dissertations

This thesis presents and explores two techniques for automated logging statement evolution. The first technique reinvigorates logging statement levels to reduce information overload using degree of interest obtained via software repository mining. The second technique converts legacy method calls to deferred execution to achieve performance gains, eliminating unnecessary evaluation overhead.

Development And Analysis Of A Vibration Based Sleep Improvement Device, Benjamin John Himes

Theses and Dissertations

Many research studies have analyzed the effect that whole-body vibration (WBV) has on sleep, and some have sought to use vibration to treat sleep disorders such as insomnia. It has been shown that low frequencies (f < 2Hz) are generally sleep inducing, but oscillations of this frequency are typically difficult to achieve using electromagnetic vibration drives. In the research that has been performed, optimal vibration parameters have not been determined, and the effects of multiple vibration sources vibrating at different frequencies to induce a low frequency traveling wave have not been explored. Insomnia affects millions of people worldwide, and non-pharmacological treatment options are limited. A bed excited with multiple vibration sources was used to explore beat frequency vibration as a non-pharmacological treatment for insomnia. A repeated measures design pilot study of 14 participants with mild-moderate insomnia symptom severity was conducted to determine the effects of beat frequency vibration, and traditional standing wave vibration on sleep latency and quality. Participants were monitored using high-density electroencephalography (HD-EEG). Sleep latency was compared between treatment conditions. Trends of a decrease in sleep latency due to beat frequency vibration were found (p ≤ 0.181 for AASM latency, and p ≤ 0.068 for unequivocal sleep latency). Neural complexity during wake, N1, and N2 stages were compared using Multi-Scale Sample Entropy (MSE), which demonstrated significantly lower MSE between wake and N2 stages (p ≤ 0.002). Lower MSE was found in the transition from wake to N1 stage sleep but did not reach significance (p ≤ 0.300). During N2 sleep, beat frequency vibration shows lower MSE than the control session in the left frontoparietal region. This indicates that beat frequency vibration may lead to a decrease of conscious awareness during deeper stages of sleep. Standing wave vibration caused reduced Alpha activity and increased Delta activity during wake. Beat frequency vibration caused increased Delta activity during N2 sleep. These preliminary results suggest that beat frequency vibration may help individuals with insomnia symptoms by decreasing sleep latency, by reducing their conscious awareness, and by increasing sleep drive expression during deeper stages of sleep. Standing wave vibration may be beneficial for decreasing expression of arousal and increasing expression of sleep drive during wake, implying that a dynamic vibration treatment may be beneficial. The application of vibration treatment as part of a heuristic sleep model is discussed.

Developing And Comparing Sensor For Movement Analysis And Biofeedback, Umaiyaal Vasudevaraja

Theses and Dissertations

Background: Recent advances in the field of wearable technology are now at a peak in the sports field and the medical field. The validity, reliability, and application of such systems are still under research and yet to be revealed.

Purpose: This study aims to design and constructing the Inertial Measurement Unit (IMU) hardware with the required software to collect accelerometer data for potential use in human movement studies and test the efficacy of the collected IMU accelerometer data by comparing it with the motion capture data.

Methods: In this study, the IMU sensor is coupled with the Arduino, loaded with …

Compiler-Based Tools To Aid In Data Transfer Optimization And On-Chip Debug Of Heterogeneous Compute Systems, Matthew B. Ashcraft

Theses and Dissertations

First, we present techniques to efficiently schedule data transfers through compiler analyses. Compared to transferring data immediately before and after the kernel executes, our scheduling results in orders of magnitude improvements in execution time, number of data transfers, and number of bytes transferred. Second, we demonstrate techniques to provide on-chip debugging for heterogeneous systems through recording execution on the software in addition to debugging circuitry in the hardware, and provide a temporal correlation between the hardware and software traces through synchronization. This allows us to follow debug data between the hardware and software trace buffers. Due to the added cost …

Viability Of Augmented Reality For Machine Maintenance, Wesley Robert Ferguson

Theses and Dissertations

Augmented reality has come a long way in the past decades in the manner of reduced costs and increased reliability. Despite these developments, there is still a difficulty bridging the gap between practical use and pure theory. This work explores if the current state of augmented reality is at a stage that can be utilized to implement solutions for heavy machinery maintenance routines by exploring the quality of education from augmented reality applications, capturing said maintenance routines for our own system, then replicating them in an augmented reality application with consumer grade equipment.

Room Temperature Semiconductor Radiation Detectors Based On Cdznte And Cdzntese, Mohsin Sajjad

Theses and Dissertations

In recent years, there have been considerable interests in nuclear radiation detectors for national security and nuclear safeguard including monitoring special nuclear materials and nuclear waste characterization, for medical imaging devices using nuclear medicine such as positron emission tomography (PET), and for NASA space astronomy. One of the most promising semiconductors being considered for the field-deployable nuclear detector is cadmium zinc telluride (CdZnTe or CZT). CZT is a ternary semiconductor that can efficiently stop and detect high-energy gamma-rays at room temperature. CZT has desirable properties for efficient nuclear radiation detection and imaging due to high atomic number (Z ~ 50, …

New Models For Truck Appointment Problem And Extensions, Mohammad Torkjazi

Theses and Dissertations

The problematic issues surrounding gate congestion at marine container terminals have been well documented. Random truck arrivals at maritime container terminals are one of the primary reasons for gate congestion. Gate congestion negatively affects the terminal’s and drayage firms’ productivity and the surrounding communities in terms of air pollution and noise. To alleviate gate congestion, more and more terminals in the U.S. are utilizing a truck appointment system (TAS).

The first study proposes a novel approach for designing a Truck Appointment System (TAS) intended to serve both the marine container terminal operator and drayage operators. The aim of the proposed …

Incorporating Stability In Deployable Origami-Based Engineering Applications, David Wayne Andrews

Theses and Dissertations

For origami-based designs to be functional, they need to be stable. Typically, stability is achieved through the introduction of exterior supports or members. This work focuses on incorporating stability into deployable origami-based engineering applications, including the development of deployable stiffeners or hard stops and generating concepts for stable origami-based systems in specific applications. Two types of deployable stiffeners are developed. Models for transcrease hard stops are presented, which can be directly implemented into origami-patterns to block motion at a specified angle. Thickness Utilizing Deployable Hard Stops (ThUDS), adapted from the transcrease hard stop models, can be implemented into thick materials …

Remediation Of Desiccation Cracking In Clayey Soils Through Bio-Cementation And Bottom Ash, Mark Vail

Theses and Dissertations

Desiccation cracking considerably impairs the hydraulic and mechanical properties of clayey soils and is critical to the long-term performance of infrastructure foundations and earth structures. Classical crack remediation methods are associated with high labor and maintenance costs or the usage of environment-unfriendly chemicals. Recycling waste materials and developing bio-mediated techniques have emerged as green and sustainable soil stabilization solutions. The objective of this study is to investigate the feasibility of soil crack remediation through the usage of microbial-induced calcite precipitation (MICP) and bottom ash admixtures. We carry out monotonic drying and cyclic drying-wetting tests to characterize the effects of bottom …

Algorithmic Robot Design: Label Maps, Procrustean Graphs, And The Boundary Of Non-Destructiveness, Shervin Ghasemlou

Theses and Dissertations

This dissertation is focused on the problem of algorithmic robot design. The process of designing a robot or a team of robots that can reliably accomplish a task in an environment requires several key elements. How the problem is formulated can play a big role in the design process. The ability of the model to correctly reflect the environment, the events, and different pieces of the problem is crucial. Another key element is the ability of the model to show the relationship between different designs of a single system. These two elements can enable design algorithms to navigate through the …

Implementation Of Cholesteric Liquid Crystals In Fibrous Based Membranes, Ydana Yanell Virgen Gracia

Theses and Dissertations

The project consists of an investigation of optical sensors. On this project, the main focus was to implement materials that had properties such as thermochromism, piezochromism, and be able to detect volatile organic compounds with a color change response. The materials selected for this project were Cholesteric Liquid Crystals (CLCs) in different combinations and ratios. There were also four different methods using Forcespinning © technology to apply the CLCs into a polymer matrix; these were, In-Solution, Dip Coating, Coaxial Spinning, and Emulsion. The best results were given by Dip Coating, but the method with the best viable solution was Coaxial …

Cis-Resveratrol Upregulates Tyrosyl-Trna Synthetase And Inhibits The Proliferation Of Select Breast Cancer Cell Lines, Marion Cone Hope Iii

Theses and Dissertations

Breast cancer is one of the most commonly occurring cancers in women. 70% of breast cancer patients express ERα and are treated with tamoxifen (Tam), a drug that is used to directly target ERα. However, 20-30% of cancer patients develop a resistance to Tam. This resistance leads to a worse prognosis and other treatments such as DNA damaging drugs or radiation to eliminate these cells. Resveratrol (RSV) is a polyphenolic- compound found in plants such as grapes and hellebore and is known to evoke anti-cancer effects. While natural resveratrol exists as a mixture of both cis- and trans- isomers, so …

17 Β-Estradiol And Phytoestrogens Attenuate Apoptotic Cell Death In Hiv-1 Tat Exposed Primary Cortical Cultures, Sheila Marie Adams

Theses and Dissertations

Despite the advent of highly active antiretroviral therapy (HAART), neurological disorders develop in most people infected with human immunodeficiency virus type 1 (HIV-1). The poor CNS delivery of anti-retrovirals allows continued virus production and renders neurons susceptible to the toxic effects of released viral proteins. The neurotoxic potential of HIV-1 viral protein Tat has been shown to include excitotoxicity, oxidative stress, and mitochondrial dysfunction leading to subsequent cell death. Thus, Tat is thought to have a key role in the pathogenesis of HIV-associated neurodegeneration. Estrogens are universally considered to be neuroprotective, as such; estrogens have positive implications in the treatment …

Solid Materials Discovery For Thin Films, Oxide Catalysts, And Polymer Sealants, Benjamin Ruiz-Yi

Theses and Dissertations

Solid materials are made up of multiple classes, including metals, ceramics, and polymers. While each class can be developed for general purpose applications or highly specialized, discovery of new materials in order to improve upon desired properties is a non-trivial task for any type of material. A wide variety of materials encompass expansive design spaces, consisting of parameters such as chemical compositions, synthesis conditions, and post-processing. Due to this, narrowing down the design space to fit within a given figure-of-merit and economic viability becomes time consuming at best and infeasible at worst. High-throughput experimentation

High-throughput experimentation (HTE) is a methodology …

Guided-Wave Shm And Nde Of Composite Structures: Modeling And Experiments, Hanfei Mei

Theses and Dissertations

The extensive use of composites in aerospace structures has posed new challenges for implementing effective structural health monitoring (SHM) and nondestructive evaluation (NDE) techniques due to the general anisotropic behavior and complex damage scenarios in composites. This dissertation addresses the SHM and NDE of composites using ultrasonic guided waves, with an emphasis on theoretical modeling and experimental validation of guided-wave propagation and interaction with damage in composites. A semi-analytical finite element (SAFE) approach is presented to calculate guided-wave dispersion curves in composites. The theoretical framework is formulated using the finite element method (FEM) to describe the material variation along the …