Digital Commons Network^™

Laser Micropatterning Effects On Corrosion Resistance Of Pure Magnesium Surfaces, Yahya Efe Yayoglu

USF Tampa Graduate Theses and Dissertations

Magnesium and its alloys are good candidates to manufacture medical implants. They have excellent biocompatibility and because they biodegrade secondary surgical operation to remove the implant could be eliminated. However, in aqueous environments, magnesium alloys rapidly corrode, resulting in premature degradation of the implant along with biologically intolerable hydrogen gas generation. In literature, there are multiple studies focused on creating water repelling hydrophobic magnesium surfaces in order to decrease corrosion rates. Hydrophobic properties can be achieved by creation of a roughness profile on an initially smooth surface combined with a treatment that reduces the free surface energy. In theory, hydrophobic …

Manipulation And Patterning Of Mammalian Cells Using Vibrations And Acoustic Forces, Joel Cooper

USF Tampa Graduate Theses and Dissertations

Recently, there has been a surge in researchers and scientists investigating different methods which move, manipulate, and pattern biological cells. Multiple different mechanisms can be used for cellular manipulation, microfluidics, biochemical queues, and even optics, just to name a few. However, all techniques have their downsides. A majority of these methods require expensive equipment or reagents and can only manipulate a small number of cells at a time.

Some of the most common cell manipulation devices utilize acoustic pressure waves to move the cells to desired locations. Currently, it is unknown what level of force from these types of devices …

Socially Aware Network User Mobility Analysis And Novel Approaches On Aerial Mobile Wireless Network Deployment, Ismail Uluturk

USF Tampa Graduate Theses and Dissertations

Service demand patterns for wireless networks are evolving with the technological developments in areas such as personal computing, unmanned vehicles, and internet-of-things, where increasing mobile service demand is one of the significant challenges introduced. In addition to these new intrinsic dynamics, natural disasters and societal upheaval are also disrupting the conventional patterns of network demand. Situations like damaged infrastructure due to a natural disaster or large numbers of displaced people caused by political strife and social upheaval demand flexible, rapidly deployable network architectures. The increasing demands of next-generation communication services are straining the capabilities of the traditional approach of the …

Lost Without A Connection: Analyzing Netflix's Maniac In The Digital Streaming Age, Eric Bruce

USF Tampa Graduate Theses and Dissertations

With the emergence and rise in popularity of streaming services such as Netflix or Hulu, the way in which audiences view and interact with media, as well as each other, has changed drastically. The move to digital streaming impacts how audiences everywhere experience and expect immediacy in media, connecting deeper with what they watch. Along with this transition in spectatorship comes a shift in visual aesthetics, a trend that can be seen across various digitally-streamed series. This thesis serves to address what this transition is and how it affects the cultural landscape of the digital age, continuing the conversation of …

Growth And Characterization Of 2d Layered Materials, Algene Fryer Ii

USF Tampa Graduate Theses and Dissertations

2D layered materials are becoming an important area of research due to their exceptional electrical and optical properties. Specifically, 2D layered monochalcogenides are known for their high carrier motilities, whereas layered metal halides have been shown to have noteworthy photoresponsivity. Despite the assortment of 2D layered materials, the search for reliable and scalable synthesis methods is still a challenge in this family of materials. Often a certain growth technique will compromise a desirable trait needed for further fabrication, such as the quality of the crystal or its coverage on a substrate. In this study, two growth techniques that incorporate changeable …

Keyless Anti-Jamming Communication Via Randomized Dsss, Ahmad Alagil

USF Tampa Graduate Theses and Dissertations

Nowadays, wireless networking is ubiquitous. In wireless communication systems, multiple nodes exchange data during the transmission time. Due to the natural use of the communication channel, it is crucial to protect the physical layer to make wireless channels between nodes more reliable. Jamming attacks consider one of the most significant threats on wireless communication. Spread spectrum techniques have been widely used to mitigate the effects of the jammer. Traditional anti-jamming approaches like Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS) require a sender and a receiver to share a secret key prior to their communication. If this …

Artificial Intelligence Towards The Wireless Channel Modeling Communications In 5g, Saud Mobark Aldossari

USF Tampa Graduate Theses and Dissertations

Channel prediction is a mathematical predicting of the natural propagation of the signal that helps the receiver to approximate the affected signal, which plays an important role in highly mobile or dynamic channels. The standard wireless communication channel modeling can be facilitated by either deterministic or stochastic channel methodologies. The deterministic approach is based on the electromagnetic theories and every single object in that environment has to be known in that propagation space and an example of this method is ray tracing. While the stochastic modeling method is based on measurements that involve statistical distributions of the channel parameters and …

Post-Overlay Flexible Pavement Performance Modeling And Its Application In Sustainable Asphalt Overlay Policy Making, Chunfu Xin

USF Tampa Graduate Theses and Dissertations

Highway pavement is a critical component of the highway transportation infrastructure. After the construction of a pavement system, pavement condition will deteriorate over time due to a combination effect of material aging, traffic loading, and environmental impact. To restore the pavement performance and to reduce its adverse effects on public users and environment, asphalt overlay activities are conducted frequently during the service life of a pavement. As a key component that bridges the overlay policies with future pavement performance, economic cost and environmental impact, the forecast accuracy of post-overlay pavement performance model is extremely important. However, most of previous studies …

Rapid Cross-Section Imaging With Magnetic And Impedance Sensors For Grout Anomaly Detection In External Post-Tensioned Tendons, Hani Freij

USF Tampa Graduate Theses and Dissertations

Post-tensioned (PT) bridges have had severe corrosion issues with tendons that fail suddenly without prior notice. The corrosion of external post-tensioned tendons has been associated with grout deficiencies/anomalies from inadequate grouting. Deficiencies include voids, regions of chalky low strength grout, and regions where excessive water content or even free water is present. In those zones mechanical bonding of strand to the grout is degraded and, of more concern, the strand steel risks corrosion failure reducing the expected lifespan of the structure. As tendons are critical structural components, it is important to detect those deficiencies during inspection preferably by a cross …

Study Of The Therapeutic Effects Of Synchronization-Modulation Of The Na/K Pump On Muscle Fatigue, Jason E. Mast

USF Tampa Graduate Theses and Dissertations

It has been shown that by applying a specially designed oscillating external electric field to a cell membrane that the membrane's sodium/potassium pumps can be synchronized to all work at the same rate. Then by slowly increasing the electric field's frequency the pumps' turnover rate can also be increased. By increasing the pumps' turnover rate, the sodium and potassium concentration gradients can be increased, this type of stimulation is called synchronization-modulation. There are three generations of the synchronization-modulation waveform each with different utilities. In particular, the third generation of synchronization-modulation has the ability to use the energy of the external …

Hybrid Electro-Plasmonic Stimulation Of Primary Neurons, Ratka Damnjanovic

USF Tampa Graduate Theses and Dissertations

Biomedical prosthetics utilizing electrical stimulation have limited, effective spatial resolution due to spread of electrical currents to surrounding tissue, causing nonselective stimulation. So, precise spatial resolution is not possible for traditional neural prosthetic devices, such as cochlear implants. More recently, alternative methods utilize optical stimulation, mainly infrared, sometimes paired with nanotechnology for stimulating action potentials, which has its own drawbacks, as it may heat surrounding tissue. Recently, we employed plasmonic stimulation methods utilizing gold nanoparticle-coated nanoelectrodes to convert visible light pulses into localized surface plasmon resonance transduction for stimulation of electrically excitable cells, which had limited success. Here, we report …

Composition Of Atomic-Obligation Security Policies, Danielle Ferguson

USF Tampa Graduate Theses and Dissertations

There has been significant work to date on policy-specification languages that allow specification of arbitrary obligations, but there continues to exist open challenges in the composition of these arbitrary obligations, especially when obligations can be complex (i.e. consist more than one action). There are currently no solutions that allow complete and automatic resolution of conflicts between policies and other policies' obligations or that allow policies to react to the complex obligations of other policies. In particular, there is minimal work that considers the benefits and challenges of allowing complex obligations that operate in an atomic fashion, that is that execute …

Models Of Secure Software Enforcement And Development, Hernan M. Palombo

USF Tampa Graduate Theses and Dissertations

Computer Security has been a pressing issue that affects our society in multiple ways. Although a plethora of security solutions have been proposed and implemented throughout the years, security continues to be a problem for at least two important reasons, (1) implementations of runtime enforcement mechanisms have not been modeled rigorously and thus may not be enforcing the policies that are expected to enforce, and (2) there are conflicting tensions in the software development process that hinder the implementation and maintenance of secure software. To investigate these issues, this dissertation is divided into two parts.

The first part of this …

Allosteric Control Of Proteins: New Methods And Mechanisms, Nalvi Duro

USF Tampa Graduate Theses and Dissertations

Allostery describes the phenomenon where perturbations in one region of a protein affect protein behavior in another non-overlapping region. Considerable efforts made over decades to understand the molecular basis of allostery, yet an overarching theory that can predict signaling pathways and contributions from chemical components is still lacking. In fact, molecular details in even the most well-studied of model systems, PDZ domains and GPCRs, remain unclear. In this dissertation I use molecular simulation methods to understand the role of allostery in the regulated entry of paramyxovirus into host cells, and also develop a new method to determine time-dependent signaling pathways …

Winning “Americans” For Jesus?: Second-Generation, Racial Ideology, And The Future Of The Brazilian Evangelical Church In The U.S., Rodrigo Otavio Serrao Santana De Jesus

USF Tampa Graduate Theses and Dissertations

Beginning in the mid-1980s, a significant number of Brazilians began to leave their country due to economic stagnation, affecting the population and the middle class in particular. This event became known as the “Brazilian Diaspora” and was characterized by a type of labor diaspora that made scholars identify Brazilian immigrants as economic refugees. In the United States, churches have been one of the most important institutions to receive and socialize Brazilians. Considering that a new generation of U.S. born Brazilian Americans emerged, this dissertation provides one of the first studies to investigate the dynamics of a second-generation Brazilian church. In …

Game Theory Approaches For Transportation Problems, Mahdi Takalloo

USF Tampa Graduate Theses and Dissertations

This dissertation considers three separate game theory problems in transportation. In the first problem, a combinatorial auction market has been proposed for fractional ownership of autonomous vehicles. The proposed combinatorial auction has two unique features. First, the items are continuous time slots defined by bidders and second, the spatial information of bidders has been incorporated so that sharing becomes a viable plan. A conflict-based formulation of the winner determination problem has been proposed, for which an effective solution approach based on a heuristic and a maximal-clique based relaxation has been presented. The second part of the dissertation examines a pessimistic …

Functional Object-Oriented Network: A Knowledge Representation For Service Robotics, David Andrés Paulius Ramos

USF Tampa Graduate Theses and Dissertations

In this dissertation, we discuss our work behind the development of the functional object-oriented network (abbreviated as FOON), a graphical knowledge representation for robotic manipulation and understanding of its own actions and (potentially) the intentions of humans in the household. Based on the theory of affordance, this representation captures manipulations and their effects on actions through the coupling of object and motion nodes as fundamental learning units known as functional units. The activities currently represented in FOON are cooking related, but this representation can be extended to other activities that involve manipulation of objects which result in observable changes of …

Toxic Colonialism And Green Victimization Of Native Americans: An Examination Of The Genocidal Impacts Of Uranium Mining, Averi R. Fegadel

USF Tampa Graduate Theses and Dissertations

While the field of criminology has delved into environmental justice issues in Black communities through the exploration of urban exposure to toxins, it has failed to expand this research orientation to examine issues affecting peoples in different locations, which in the U.S. draws attention to the green victimization of Native Americans. In short, existing criminological research has largely ignored the social, economic, and environmental injustices experienced by Native Americans. This study addresses this research gap by exploring environmental justice issues as they relate to the ways toxic colonialism affects Native Americans. Specifically, this study confronts historic and current struggles endured …

Investigating Mechanisms Of Immune Suppression Secondary To An Inflammatory Microenvironment, Wendy Michelle Kandell

USF Tampa Graduate Theses and Dissertations

The immune system plays a dynamic role in cancer progression. The theory of immunoediting suggests that the relationship between the tumor cell and the immune cell is one that is in flux: initially highly active and responsive to tumor antigen to one that has escaped immune responsiveness. Once the tumor has formed and effectively “escaped”, there are multiple mechanisms that work against a conventional immune response. The tumor cell clones that have escaped the elimination phase are those that are less immunogenic. These clones downregulate MHC, have increased apoptosis through DAMP-driven mechanisms, and suppressive cell phenotypes are driven through cytokine-driven …

Development Of A Monolithic Implantable Neural Interface From Cubic Silicon Carbide And Evaluation Of Its Mri Compatibility, Mohammad Beygi

USF Tampa Graduate Theses and Dissertations

One of the main issues with micron-sized intracortical neural interfaces (INIs) is their long-term reliability, with one major factor stemming from device material failure caused by the heterogeneous integration of multiple materials used to realize the implant. Single crystalline cubic silicon carbide (3C-SiC) is a semiconductor material that has been long recognized for its mechanical robustness and chemical inertness. It has the benefit of demonstrated biocompatibility, which makes it a promising candidate for chronically-stable, implantable INIs. In the first section of this dissertation, the fabrication and initial electrochemical characterization of a monolithic, Michigan-style 3C-SiC microelectrode array (MEA) probe is reported. …

Bond Life Of Structural Epoxy-Concrete Systems Under Accelerated Hygrothermal Aging, Philip W. Hopkins

USF Tampa Graduate Theses and Dissertations

A laboratory study was conducted to investigate possible quantitative and qualitative methods for determining the bond life of structural epoxies externally bonded to concrete substrates. Three concrete mixtures, two surface preparation methods, and three structural epoxies were used creating eighteen combinations of bonded systems. Direct tension (pull-off) specimens were prepared from which a subset was submerged in heated water per a prescribed accelerated aging protocol for up to 200 days. A novel test fixture was designed to facilitate controlled-rate testing of the pull-off specimens. A total of 324 specimens were intermittently removed from submersion exposure and tested without replacement. An …

Design Of Delro Autonomous Delivery Robot And Ai Based Localization, Tolga Karakurt

USF Tampa Graduate Theses and Dissertations

Autonomous robots are employed in numerous areas. In this thesis, it is proposed to design and build a self-controlled wheeled vehicle to deliver food.

As there are many applications of an autonomous agent for indoor and outdoor environments, this study is conducted on indoor settings whereas all the requirements and design processes are achieved for both operational boundaries.

The fundamental approach is to design and implement a Wheeled Mobile Robot (WMR), and to test skid-steering performance on proposed trajectories using a System Engineering approach. From this point of view, system requirements in mechanical, electrical, and software are evaluated, and overall …

Novel Bit-Sliced In-Memory Computing Based Vlsi Architecture For Fast Sobel Edge Detection In Iot Edge Devices, Rajeev Joshi

USF Tampa Graduate Theses and Dissertations

For today’s Internet-of-Things (IoT) edge devices, there is an acute need for fast and power-efficient hardware for an image processing task. Traditional hardware solutions with sequential and/or pipelined architectures incur high latency and power. This motivates us to propose a novel in-memory computing architecture for rapid image processing. We propose a bit-sliced in-memory computing architecture for CMOS VLSI implementation for fast Sobel edge detection. To the best of our knowledge, this is the first work to propose in-memory computing based VLSI architecture foredge detection. The novelty of the proposed work is that one image can be processed in constant time …

Role Of Thyroid Hormone Modulating Astrocyte Activation, Payal Ghosh

USF Tampa Graduate Theses and Dissertations

Astrocytes are the specialized cells in the central nervous system (CNS). They play an important role in neuronal homeostasis. When activated, astrocytes may cause neuronal inflammation and degeneration. Thyroid hormones are important in maintaining neuronal development and homeostasis. Astrocytes play a pivotal role in this process. However, the role of levothyroxine (T4) in neuroinflammation is not clear. It is hypothesized that thyroid hormone treatment will reduce the inflammatory activation in astrocytes. Available oral T4 supplementations allow accumulation of T4 in the body and cause toxicity and side effects. It is hypothesized that the encapsulation of T4 in liposomes would reduce …

Influence Of Glass Fiber Reinforced Polymer Wraps On Corrosion Progression Of Bridge Piles In Marine Environments, Shayan Yazdani

USF Tampa Graduate Theses and Dissertations

The Friendship Trail Bridge connecting Tampa to St. Petersburg was demolished in 2016. Thirteen 20 inches. by 20 inches. reinforced concrete piles supporting its superstructure were part of research studies conducted between 2004 and 2008 to explore the role of glass fiber reinforced polymers (GFRP) in corrosion repair. During demolition, piles were typically cut at the pile cap and in the splash zone. The resulting segments varied in length between 3 to 4 ft. These remnants were transported to the University of South Florida (USF) campus for postmortem analysis. The overarching goal was to establish the role of GFRP in …

Academic Digital Badges: Industry, Employment, And Prospects, Terry M. Mcgovern

USF Tampa Graduate Theses and Dissertations

Digital badges are becoming more prevalent in the credentialing sector yet there is limited understanding of how the industry is developing or how digital badges influence the hiring process. This study employed an exploratory case method to make known the development of the badging industry. This dynamic new educational technology has a wide range of stakeholders working at establishing standards to ensure consistent and effective application across the badging ecosphere. To understand academic badging further, the researcher conducted a type of field experiment called a résumé audit study. In the late Spring of 2019, the investigator applied to 1,848 unique …

Investigation Of Machine Learning Algorithms For Intrusion Detection System In Cybersecurity, Mohmmed Alrowaily

USF Tampa Graduate Theses and Dissertations

The proliferation in usage and complexity of modern communication and network systems, a large number of trustworthy online Services and systems have been deployed. Even so, cybersecurity threats are still growing. An Intrusion Detection System (IDS) play a vital role in ensuring the security of communication networks, and it is taken into account as the subsequent security gate after the firewall. The IDS informs the system or network administrator in order to take specific actions to evade the suspicious activities. Three significant contributions are made during the course of this research to illustrate the feasibility of these IDS approaches. In …

Growth And Characterization Of Spatially Ordered Nanostructures Of Functional Materials, Domingo J. Mateo Feliciano

USF Tampa Graduate Theses and Dissertations

Thin films and nanostructures of functional materials like lead zirconium titanite oxide (PZT) and Zinc Oxide (ZnO) offer multitude of applications in ferroelectrics, piezoelectrics and piezotronics. While the properties of thin films of ZnO and PZT are well understood, methods for the fabrication of vertically-aligned and spatially ordered nanocolumns of these materials are not common. To achieve a spatially ordered arrangement of either PZT or ZnO, a Silica Nanosphere (SNS) Monolayer Template has been constructed to serve as nucleation site for the growth of a specific number of nanocolumns. The SNS monolayer template is constructed by Langmuir-Blodgett dip coating, using …

Women In Water: An Interpretative Phenomenological Analysis Of Women's Lived Experience As Water And Wastewater Professionals, Pamela Murawski

USF Tampa Graduate Theses and Dissertations

The purpose of this interpretative phenomenological analysis was to explore the lived experiences of women water and wastewater professionals in California. A qualitative methodology and semi-structured interviews provided detail and a rich understanding of women’s occupational choices, pursuits, and roles as told from their own perspectives. The results revealed that while working in water promoted a sense of pride, accomplishment, and empowerment, women continued to fight for equal access and full participation in lucrative water treatment careers. Key issues the women indicated were lack of knowledge of the industry, the necessity of mentorship, access to technical information, and the male-centered …

Enhancement Of 5g Network Performance Using Non-Orthogonal Multiple Access (Noma), Faeik Tayseer Al Rabee

USF Tampa Graduate Theses and Dissertations

This dissertation is composed of two parts. The first presents several approaches to enhance the performance of 5G wireless systems by using NOMA (Non-Orthogonal Multiple Access) as the multiple access technique under different scenarios and performance metrics. The second investigates the performance of a wireless system network using a mobility model to evaluate the channel capacity taking into account motion. Both studies are directed towards improving the system performance in wireless communication systems.

In the first part, the optimum received power level for uplink power-domain NOMA with ideal Successive Interference Cancellation (SIC) reception is derived for any number of transmitters. …