Degree Level

The Relation of Sport Involvement and Gender to Fitness, Self-Efficacy, and Self-Concept in Middle School Students (open access)

The Relation of Sport Involvement and Gender to Fitness, Self-Efficacy, and Self-Concept in Middle School Students

In the current study, the relation of the frequency of sport participation and gender to CRF, muscular strength and flexibility, body composition, physical activity self-efficacy, and physical self-concept in a sample of 629 sixth graders were examined. Because both physical activity and sport participation have been related to similar outcomes, activity through physical education was controlled by including only 6th graders who were part of a required school class. MANCOVA analyses demonstrated that sport involvement was significantly related to improvements in physical fitness (i.e., CRF and muscular strength), physical activity self-efficacy, and physical self-concept (CRF and muscular strength). The interaction between sport involvement and gender was not significant, suggesting these relationships existed equally for the boys and girls.
Date: May 2017
Creator: Clevinger, Kristina J.
System: The UNT Digital Library
Replenishment: A Musical Narrative Inspired by Sleep (open access)

Replenishment: A Musical Narrative Inspired by Sleep

The Replenishment cycle contains five works that allude to the experience of sleep, beginning with awake drowsiness and ending with the piece inspired by rapid eye movement (REM) sleep, titled Conceiving Realities. This last piece is an intermedia work composed for chamber ensemble, live painting with biofeedback, computer, and audiovisual processing. This critical essay describes the composition of Conceiving Realities within the context of the Replenishment cycle, followed by a thorough analysis of the research involved in the technological aspects of the piece, and finally, a description of the instrumentation, notation, intermedia elements, and technology comprising the work. Conceiving Realities uses a system of interactions between painting, biofeedback, music, and video, in which a painter wears brainwave and heartbeat sensors that send data to a computer patch processing the sound of an ensemble as the painter listens and creates the painting while responding to the music. This requires a passive biofeedback system in which the painter is focused on listening and painting. The computer uses the data to process existing sounds, instead of synthesizing new lines. The score blends elements of traditional notation, graphics, and guided improvisation; giving the performers some creative agency. This alludes to the way in which …
Date: December 2017
Creator: Espinel, Miguel Angel
System: The UNT Digital Library
Formation Control of Multi-Agent Systems (open access)

Formation Control of Multi-Agent Systems

Formation control is a classical problem and has been a prime topic of interest among the scientific community in the past few years. Although a vast amount of literature exists in this field, there are still many open questions that require an in-depth understanding and a new perspective. This thesis contributes towards exploring the wide dimensions of formation control and implementing a formation control scheme for a group of multi-agent systems. These systems are autonomous in nature and are represented by double integrated dynamics. It is assumed that the agents are connected in an undirected graph and use a leader-follower architecture to reach formation when the leading agent is given a velocity that is piecewise constant. A MATLAB code is written for the implementation of formation and the consensus-based control laws are verified. Understanding the effects on formation due to a fixed formation geometry is also observed and reported. Also, a link that describes the functional similarity between desired formation geometry and the Laplacian matrix has been observed. The use of Laplacian matrix in stability analysis of the formation is of special interest.
Date: August 2017
Creator: Mukherjee, Srijita
System: The UNT Digital Library
Human-Machine Interface Using Facial Gesture Recognition (open access)

Human-Machine Interface Using Facial Gesture Recognition

This Master thesis proposes a human-computer interface for individual with limited hand movements that incorporate the use of facial gesture as a means of communication. The system recognizes faces and extracts facial gestures to map them into Morse code that would be translated in English in real time. The system is implemented on a MACBOOK computer using Python software, OpenCV library, and Dlib library. The system is tested by 6 students. Five of the testers were not familiar with Morse code. They performed the experiments in an average of 90 seconds. One of the tester was familiar with Morse code and performed the experiment in 53 seconds. It is concluded that errors occurred due to variations in features of the testers, lighting conditions, and unfamiliarity with the system. Implementing an auto correction and auto prediction system will decrease typing time considerably and make the system more robust.
Date: December 2017
Creator: Toure, Zikra
System: The UNT Digital Library
Design of a Machine Condition Monitoring System with Bluetooth Low Energy (open access)

Design of a Machine Condition Monitoring System with Bluetooth Low Energy

This thesis discusses the design considerations for a machine conditioning sensor utilizing Bluetooth low energy (BLE).
Date: May 2017
Creator: Tompkins, Nicholas
System: The UNT Digital Library
Brain Computer Interface (BCI) Applications: Privacy Threats and Countermeasures (open access)

Brain Computer Interface (BCI) Applications: Privacy Threats and Countermeasures

In recent years, brain computer interfaces (BCIs) have gained popularity in non-medical domains such as the gaming, entertainment, personal health, and marketing industries. A growing number of companies offer various inexpensive consumer grade BCIs and some of these companies have recently introduced the concept of BCI "App stores" in order to facilitate the expansion of BCI applications and provide software development kits (SDKs) for other developers to create new applications for their devices. The BCI applications access to users' unique brainwave signals, which consequently allows them to make inferences about users' thoughts and mental processes. Since there are no specific standards that govern the development of BCI applications, its users are at the risk of privacy breaches. In this work, we perform first comprehensive analysis of BCI App stores including software development kits (SDKs), application programming interfaces (APIs), and BCI applications w.r.t privacy issues. The goal is to understand the way brainwave signals are handled by BCI applications and what threats to the privacy of users exist. Our findings show that most applications have unrestricted access to users' brainwave signals and can easily extract private information about their users without them even noticing. We discuss potential privacy threats posed by …
Date: May 2017
Creator: Bhalotiya, Anuj Arun
System: The UNT Digital Library
Academic and Social Functioning of College Students with Attention-Deficit/Hyperactivity Disorder (ADHD) (open access)

Academic and Social Functioning of College Students with Attention-Deficit/Hyperactivity Disorder (ADHD)

Attention-deficit/hyperactivity disorder (ADHD) is a complicated psychiatric disorder that is typically first diagnosed in childhood and associated with negative outcomes in adulthood such as poor academic performance and difficulties with social relationships. ADHD can be difficult to accurately diagnose in adulthood, given the absence of clear, agreed upon ADHD symptomology in adults. In the current study, two raters used psychometrically sound instruments and diagnostically valid assessment techniques on an archival dataset to create three distinct groups: ADHD [2/3 with other mental health diagnosis (OMH)], OMH only, and no diagnosis. Findings support the value of comprehensive assessment, combined with a thorough evaluation of the material by a trained clinician, for the accurate diagnosis of ADHD for research purposes. Comparisons were made across groups to infer that college students with ADHD have lower grade point averages and academic self-concept than students without mental health diagnoses. Yet, contrary to much of the current literature, college students with ADHD seem to create as strong, deep, supportive and harmonious relationships with loved ones and close friends as their non-diagnosed peers. Clinicians working with college students with ADHD may use the results of the current study to better inform conceptualization, better recognize the innate resilience college …
Date: December 2017
Creator: Calmenson, Nina
System: The UNT Digital Library
A Decision-Making Model for Safe and Effective Use of Functional Analysis Procedures (open access)

A Decision-Making Model for Safe and Effective Use of Functional Analysis Procedures

While functional analysis provides the standard methodology for the assessment of problem behavior, procedures still pose potential risk when assessing severe problem behavior. Previous studies have examined several strategies to improve the efficiency of and reduce risks related to the functional analysis process. The purpose of the present series of studies was to replicate and extend previous research on the assessment and treatment of severe problem behavior for one participant diagnosed with an intellectual disability. By incorporating strategies within a systematic decision-making framework, functional analysis procedures were implemented to conduct the assessment of precursors, determine maintaining contingencies for severe problem behavior, and evaluate the effects of a treatment based on the results of a functional analysis.
Date: August 2017
Creator: Vega, Gabrielle M.
System: The UNT Digital Library
Reinforcing Variability Produces Stereotypic Behavior (open access)

Reinforcing Variability Produces Stereotypic Behavior

Behaving in novel ways is essential to the development of the types of complex performances described by the term creativity, problem solving, and perseverance. Some research suggests that response variability is an operant and a critical component of novel behavior. However, other account of novel behavior may be more parsimonious. Topographical variability has rarely been examined, nor has operant variability with organisms with baselines featuring stereotypic responding. This study examined the effects of a variability-specifying contingency on the cumulative novel responses of undergraduate students. Using the PORTL apparatus, participants interacted with a ball with a single hand. When the variability-specifying contingency was in effect, novel topographies were reinforced. When a reinforce every response condition was implemented, the participants did not emit any novel responses. When variability-specifying contingencies were in effect, novel responses were rarely followed by subsequent novel responses. They were mostly followed by repeated emission of the same topography, or by other previously emitted topographies. Novel responding did not persist long, although the variability-specifying contingency remained in effect and the potential for novel responding was great. The variability-specifying contingency often resulted in stereotypic response chains. Each of these findings call into the question the assertion that variability is an …
Date: May 2017
Creator: Kieta, Andrew R.
System: The UNT Digital Library
Probabilistic Analysis of Contracting Ebola Virus Using Contextual Intelligence (open access)

Probabilistic Analysis of Contracting Ebola Virus Using Contextual Intelligence

The outbreak of the Ebola virus was declared a Public Health Emergency of International Concern by the World Health Organisation (WHO). Due to the complex nature of the outbreak, the Centers for Disease Control and Prevention (CDC) had created interim guidance for monitoring people potentially exposed to Ebola and for evaluating their intended travel and restricting the movements of carriers when needed. Tools to evaluate the risk of individuals and groups of individuals contracting the disease could mitigate the growing anxiety and fear. The goal is to understand and analyze the nature of risk an individual would face when he/she comes in contact with a carrier. This thesis presents a tool that makes use of contextual data intelligence to predict the risk factor of individuals who come in contact with the carrier.
Date: May 2017
Creator: Gopalakrishnan, Arjun
System: The UNT Digital Library
Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces (open access)

Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces

The objective of this research was to investigate the performance of two-phase spray cooling with HFC-134a and HFO-1234yf refrigerants using practical enhanced heat transfer surfaces. Results of the study were expected to provide a quantitative spray cooling performance comparison with working fluids representing the current and next-generation mobile air conditioning refrigerants, and demonstrate the feasibility of this approach as an alternative active cooling technology for the thermal management of high heat flux power electronics (i.e., IGBTs) in electric-drive vehicles. Potential benefits of two-phase spray cooling include achieving more efficient and reliable operation, as well as compact and lightweight system design that would lead to cost reduction. The experimental work involved testing of four different enhanced boiling surfaces in comparison to a plain reference surface, using a commercial pressure-atomizing spray nozzle at a range of liquid flow rates for each refrigerant to determine the spray cooling performance with respect to heat transfer coefficient (HTC) and critical heat flux (CHF). The heater surfaces were prepared using dual-stage electroplating, brush coating, sanding, and particle blasting, all featuring "practical" room temperature processes that do not require specialized equipment. Based on the obtained results, HFC-134a provided a better heat transfer performance through higher HTC and …
Date: August 2017
Creator: Altalidi, Sulaiman Saleh
System: The UNT Digital Library
Sustainable Ecofriendly Insulation Foams for Disaster Relief Housing (open access)

Sustainable Ecofriendly Insulation Foams for Disaster Relief Housing

Natural disasters are affecting a significant number of people around the world. Sheltering is the first step in post-disaster activities towards the normalization of the affected people's lives. Temporary housing is being used in these cases until the construction of permanent houses are done. Disposal of temporary housing after use is leading to a significant environmental impact because most of them are filled with thermally insulative polymer foams that do not degrade in a short period. To reduce these problems this work proposes to use foams made with compostable thermoplastic polylactic acid (PLA) and degradable kenaf core as filler materials; these foams are made using CO2 as blowing agent for insulation purposes. Foams with PLA and 5%, 10% and 15% kenaf core were tested. Different properties and their relations were examined using differential scanning calorimetry (DSC), thermal conductivity, mechanical properties, scanning electron microscopy (SEM), x-ray μ-computed tomography (μ-CT) and building energy simulations were done using Energy Plus by NREL. The results show that mechanical properties are reduced with the introduction of kenaf core reinforcement while thermal conductivity display a noticeable improvement.
Date: May 2017
Creator: Chitela, Yuvaraj Reddy
System: The UNT Digital Library
Investigation of Spray Cooling Schemes for Dynamic Thermal Management (open access)

Investigation of Spray Cooling Schemes for Dynamic Thermal Management

This study aims to investigate variable flow and intermittent flow spray cooling characteristics for efficiency improvement in active two-phase thermal management systems. Variable flow spray cooling scheme requires control of pump input voltage (or speed), while intermittent flow spray cooling scheme requires control of solenoid valve duty cycle and frequency. Several testing scenarios representing dynamic heat load conditions are implemented to characterize the overall performance of variable flow and intermittent flow spray cooling cases in comparison with the reference, steady flow spray cooling case with constant flowrate, continuous spray cooling. Tests are conducted on a small-scale, closed loop spray cooling system featuring a pressure atomized spray nozzle. HFE-7100 dielectric liquid is selected as the working fluid. Two types of test samples are prepared on 10 mm x 10 mm x 2 mm copper substrates with matching size thick film resistors attached onto the opposite side, to generate heat and simulate high heat flux electronic devices. The test samples include: (i) plain, smooth surface, and (ii) microporous surface featuring 100 μm thick copper-based coating prepared by dual stage electroplating technique. Experimental conditions involve HFE-7100 at atmospheric pressure and 30°C and ~10°C subcooling. Steady flow spray cooling tests are conducted at flow …
Date: May 2017
Creator: Yata, Vishnu Vardhan Reddy
System: The UNT Digital Library
Estimating Thermal Conductivity and Volumetric Specific Heat of a Functionally Graded Material using Photothermal Radiometry (open access)

Estimating Thermal Conductivity and Volumetric Specific Heat of a Functionally Graded Material using Photothermal Radiometry

Functionally graded materials (FGMs) are inhomogeneous materials in which the material properties vary with respect to space. Research has been done by scientific community in developing techniques like photothermal radiometry (PTR) to measure the thermal conductivity and volumetric heat capacity of FGMs. One of the problems involved in the technique is to solve the inverse problem, i.e., estimating the thermal properties after the frequency scan has been obtained. The present work involves finding the unknown thermal conductivity and volumetric heat capacity of the FGMs by using finite volume method. By taking the flux entering the sample as periodic and solving the discretized 1-D thermal wave field equation at a frequency domain, one can obtain the complex temperatures at the surface of the sample for each frequency. These complex temperatures when solved for a range of frequencies gives the phase vs frequency scan which can then be compared to original frequency scan obtained from the PTR experiment by using a residual function. Brute force and gradient descent optimization methods have been implemented to estimate the unknown thermal conductivity and volumetric specific heat of the FGMs through minimization of the residual function. In general, the spatial composition profile of the FGMs can …
Date: December 2017
Creator: Koppanooru, Sampat Kumar Reddy
System: The UNT Digital Library
Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths (open access)

Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths

The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically monitored with several parameters including oxidation-reduction potential, conductivity, and specific gravity. However, the etch rate and etch factor can be difficult to control even under strict engineering controls of those monitoring parameters. The mechanism of acidic cupric chloride etching, regeneration and recovery is complex, and the current monitoring strategies can have difficulty controlling the interlocking chemical equilibria. A complimentary tool, thin-film UV-Vis spectroscopy, can be utilized to improve the current monitoring strategies, as UV-Vis is capable of identifying and predicting etching behavior that the current standard methodologies have difficulty predicting. Furthermore, as a chemically-sensitive probe, UV-Vis can investigate the complex changes to the chemical equilibrium and speciation of the etch bath, and can contribute overall to significant improvements in the control of the copper etching system in order to …
Date: August 2017
Creator: Lambert, Alexander S.
System: The UNT Digital Library
Practical Evaluation of a Software Defined Cellular Network (open access)

Practical Evaluation of a Software Defined Cellular Network

This thesis proposes a design of a rapidly deployable cellular network prototype that provides voice and data communications and it is interoperable with legacy devices and the existing network infrastructure. The prototype is based on software defined radio and makes use of IEEE 802.11 unlicensed wireless radio frequency (RF) band for backhaul link and an open source GSM implementation software. The prototype is also evaluated in environments where there is limited control of the radio frequency landscape, and using Voice Over Internet Protocol (VoIP) performance metrics to measure the quality of service. It is observed that in environments where the IEEE 802.11 band is not heavily utilized, a large number of calls are supported with good quality of service. However, when this band is heavily utilized only a few calls can be supported as the quality of service rapidly degrades with increasing number of calls, which is due to interference. It is concluded that in order to achieve tolerable voice quality, unused licensed spectrum is needed for backhaul communication between base stations.
Date: May 2017
Creator: Agbogidi, Oghenetega
System: The UNT Digital Library
Spectrum Analysis and Prediction Using Long Short Term Memory Neural Networks and Cognitive Radios (open access)

Spectrum Analysis and Prediction Using Long Short Term Memory Neural Networks and Cognitive Radios

One statement that we can make with absolute certainty in our current time is that wireless communication is now the standard and the de-facto type of communication. Cognitive radios are able to interpret the frequency spectrum and adapt. The aim of this work is to be able to predict whether a frequency channel is going to be busy or free in a specific time located in the future. To do this, the problem is modeled as a time series problem where each usage of a channel is treated as a sequence of busy and free slots in a fixed time frame. For this time series problem, the method being implemented is one of the latest, state-of-the-art, technique in machine learning for time series and sequence prediction: long short-term memory neural networks, or LSTMs.
Date: December 2017
Creator: Hernandez Villapol, Jorge Luis
System: The UNT Digital Library
Quia Emptores, Subinfeudation, and the Decline of Feudalism in Medieval England: Feudalism, it is Your Count that Votes (open access)

Quia Emptores, Subinfeudation, and the Decline of Feudalism in Medieval England: Feudalism, it is Your Count that Votes

The focus of this thesis is threefold. First, Edward I enacted the Statute of Westminster III, Quia Emptores in 1290, at the insistence of his leading barons. Secondly, there were precedents for the king of England doing something against his will. Finally, there were unintended consequences once parliament passed this statute. The passage of the statute effectively outlawed subinfeudation in all fee simple estates. It also detailed how land was able to be transferred from one possessor to another. Prior to this statute being signed into law, a lord owed the King feudal incidences, which are fees or services of various types, paid by each property holder. In some cases, these fees were due in the form of knights and fighting soldiers along with the weapons and armor to support them. The number of these knights owed depended on the amount of land held. Lords in many cases would transfer land to another person and that person would now owe the feudal incidences to his new lord, not the original one. This amount collected by the lord effectively reduced the payments to the original lord. During the early Middle Ages, feudal incidences began to change to a monetary exchange which …
Date: August 2017
Creator: Garofalo, Michael D.
System: The UNT Digital Library
A Study on the System Reliability of Cold-Formed Steel Roof Trusses (open access)

A Study on the System Reliability of Cold-Formed Steel Roof Trusses

This thesis presents a research project aimed at advancing the treatment of cold-formed steel (CFS) structural reliability in roof trusses. Structural design today relies almost exclusively on component-level design, so structural safety is assured by limiting the probability of failure of individual components. Reliability of the entire system is typically not assessed, so in a worst-case scenario the system reliability may be less than the component reliability, or in a best-case scenario the system reliability may be much greater than the component reliability. A roof truss itself, is a subsystem with several possible failure modes that are being studied in this test program. These trusses are constructed of CFS members that nest with one another at the truss nodes and are connected by drilling fasteners through the mated surfaces, as well as having steel sheathing fastened to the top chords for lateral bracing. Presented in this paper is a series of full-scale static tests on single cold-formed steel roof trusses with a unique experimental setup. The test specimens were carefully monitored to address multiple failure modes: buckling of the top chord, buckling of the truss webs, and any connection failures. This research includes the experimental results, the computed system reliability …
Date: May 2017
Creator: Johnson, Adam M.
System: The UNT Digital Library
Development and Analysis of a Mobile Node Tracking Antenna Control System (open access)

Development and Analysis of a Mobile Node Tracking Antenna Control System

A wireless communication system allows two parties to exchange information over long distances. The antenna is the component of a wireless communication system that allows information to be converted into electromagnetic radiation that propagates through the air. A system using an antenna with a highly directional beam pattern allows for high power transmission and reception of data. For a directional antenna to serve its purpose, it must be accurately pointed at the object it is communicating with. To communicate with a mobile node, knowledge of the mobile node's position must be gained so the directional antenna can be regularly pointed toward the moving target. The Global Positioning System (GPS) provides an accurate source of three-dimensional position information for the mobile node. This thesis develops an antenna control station that uses GPS information to track a mobile node and point a directional antenna toward the mobile node. Analysis of the subsystems used and integrated system test results are provided to assess the viability of the antenna control station.
Date: August 2017
Creator: Hensley, Phillip H.
System: The UNT Digital Library
A Conjugate Arrangement for Measuring Commercial Viewing (open access)

A Conjugate Arrangement for Measuring Commercial Viewing

Commercial viewing was measured by a conjugate arrangement for 1 female and 3 male participants. Reinforcing qualities were evaluated according to screen variations and ratings. Subjects changed the screen clarity via knob pressing either making the screen more or less transparent, translucent or opaque based on commercial interest. Results were conducive to participant attentiveness or indifference to commercial viewing. Experimenter was able to identify the commercials that grasped and maintained the participants' viewing behavior. Conceptually this conjugate arrangement could enhance eye tracking technology to improve marketing and advertising strategies. This experiment yield results that suggest a more concrete analysis of consumer response to visual stimuli that maintains attending.
Date: August 2017
Creator: Morgan, Amber
System: The UNT Digital Library
Relations among Parental Responding to Offspring Emotion, Emotion Approach Coping, and Posttraumatic Stress Symptoms among Trauma-Exposed College Students (open access)

Relations among Parental Responding to Offspring Emotion, Emotion Approach Coping, and Posttraumatic Stress Symptoms among Trauma-Exposed College Students

The present investigation evaluated whether dispositional use of emotional approach coping partially accounts for the association between parental response to emotional expression and posttraumatic stress symptoms (PTSS) in a sample of 252 trauma-exposed individuals drawn from a pool of college students and college-age members of the community at-large. An online survey assessed parental reactions to participants' negative emotions during childhood (i.e., offspring retrospective report), as well as participant trauma history, PTSS, and use of emotional approach coping. Findings complement literature illustrating the long-lasting implications of the parent-child relationship, such that both supportive and unsupportive parenting were related to PTSS. Supportive parental reactions also were related to emotional expression, but not emotional processing, and unsupportive reactions did not significantly relate to either aspect of emotional approach coping. Notably, emotional approach coping strategies were unrelated to PTSS in the full sample, and thus the indirect effects models were not supported. Post hoc analyses indicated preliminary support for the indirect effect of emotional expression on the relation between supportive parenting and PTSS in the local college student sample (n = 117). Limitations and implications for future research are discussed.
Date: May 2017
Creator: Dziurzyński, Kristan E.
System: The UNT Digital Library
Civil Liberties and National Unity: Reaction to the Sedition Act in the Southern States, 1798 (open access)

Civil Liberties and National Unity: Reaction to the Sedition Act in the Southern States, 1798

The traditional narrative of political party development in the United States of America during the latter half of the 1790s ascribes the decline in popularity of the Federalist Party in the Election of 1800 to that party's passage of controversial legislation, specifically the Sedition Act of 1798, prior to the election. Between the passage of the Sedition Act and the Election of 1800, however, the midterm elections of 1798-1799 transpired and resulted in a significant increase in Federalist popularity in four states – North Carolina, South Carolina, Georgia, and Virginia. This study seeks to ascertain why these four states increased their support for the Federalist Party in 1798-1799, despite the passage of the Sedition Act by the Federalist Party. By examining newspapers and election results, this study analyzes the reaction of these four states to the passage of the Sedition Act and finds that generally, these states did not react strongly against the Sedition Act in the immediate aftermath of its passage. Instead, all four states urged national unity and emphasized the need to support the national government because the United States faced the threat of war with France. This study employs a state-by-state formula to determine each state's individual …
Date: December 2017
Creator: Robinson, Sarah Elizabeth
System: The UNT Digital Library
Application of High Entropy Alloys in Stent Implants (open access)

Application of High Entropy Alloys in Stent Implants

High entropy alloys (HEAs) are alloys with five or more principal elements. Due to these distinct concept of alloying, the HEA exhibits unique and superior properties. The outstanding properties of HEA includes higher strength/hardness, superior wear resistance, high temperature stability, higher fatigue life, good corrosion and oxidation resistance. Such characteristics of HEA has been significant interest leading to researches on these emerging field. Even though many works are done to understand the characteristic of these HEAs, very few works are made on how the HEAs can be applied for commercial uses. This work discusses the application of High entropy alloys in biomedical applications. The coronary heart disease, the leading cause of death in the United States kills more than 350,000 persons/year and it costs $108.9 billion for the nation each year in spite of significant advancements in medical care and public awareness. A cardiovascular disease affects heart or blood vessels (arteries, veins and capillaries) or both by blocking the blood flow. As a surgical interventions, stent implants are deployed to cure or ameliorate the disease. However, the high failure rate of stents has lead researchers to give special attention towards analyzing stent structure, materials and characteristics. Many works related to …
Date: May 2017
Creator: Alagarsamy, Karthik
System: The UNT Digital Library