Engineering Commons^™

Interference Of Light In Multilayer Metasurfaces: Perfect Absorber And Antireflection Coating, Khagendra Prasad Bhattarai

USF Tampa Graduate Theses and Dissertations

We have studied several metamaterials structures with multiple layers by explaining them theoretically and verifying experimentally. The engineered structures we have designed work either as a perfect absorber or antireflection coating. The multilayer model as we call it Three Layer Model (TLM) has been developed, which gives the total reflection and transmission as a function of reflection and transmission of individual layers. By manipulating the amplitude and phase of the reflection and the transmission of the individual layers, we can get the required functionality of the optoelectronic devices. To get zero reflection in the both perfect absorber and the antireflection …

Exploring Therapeutic Approaches For Marfan Syndrome Associated Aortic Aneurysm, Mitra Esfandiarei

Science Seminar Series

Esfandiearei will be discussing her research on understanding the underlying mechanisms contributing to the progression of aortic aneurysm in Marfan syndrome and the protective effects that exercise may have on the disease process in both laboratory animal models and human patients. Her research has been supported by the Canadian Institutes of Health Research (CIHR), Rare Diseases Foundation, and the Marfan Foundation.

Congratulations A-Pin Recipients | College Of Engineering, Usu College Of Engineering

College of Engineering News

Interim College of Engineering Dean Dr. Jagath Kaluarachchi and department heads from across the College of Engineering on Thursday recognized eight students for receiving the prestigious A-Pin award.

Real-Time Insight : Developing A Internal Library Data Dashboard, Travis Clamon

ETSU Faculty Works

Library systems are becoming increasingly open, providing API’s that can deliver data in real-time. ETSU Library staff wanted a way to collect metrics from various systems and present it in one centralized dashboard. This presentation will cover our experiences with the project, including successes, challenges, and future goals.

Neuropeptide Modulation Of The Large Conductance Potassium (Bk) Channel In The Auditory System: Therapeutic Implications For Age-Related Hearing Loss, Ellliott James Brecht

USF Tampa Graduate Theses and Dissertations

The auditory temporal processing deficits associated with age-dependent hearing decline have been increasingly attributed to issues beyond peripheral hearing loss. Age-related hearing loss (ARHL), also known as presbycusis, is linked with changes in the expression of both excitatory and inhibitory neurotransmitters in the central auditory system. There are also age-related changes in the expression and function of the ion channels which mediate action potential firing. The slow, Ca²⁺ activated, K⁺ channels of the BK-type are essential in controlling both neurotransmitter release and neural communication via alteration of action potential durations, firing frequency, and neural adaptation. There are many …

A Novel Biochamberfor Modeling Of Atherosclerotic Arteries: In Vitro Capabilities And Applications, Iman Salafian, Angelos Karagiannis, Benjamin S. Terry, Yiannis S. Chatzizisis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is a chronic disease that involves the lipid accumulation and inflammation of the arterial wall [1,2]. Despite great efforts,its pathophysiology has not been fully elucidated. Existent drugs can reduce its progression but there are no available drugs to prevent its complications [3,4]. Atherosclerosis remains the leading global cause of death[5].

The purpose of this work is to design and build a customized biochamber which can be used for the following studies:

•Study the pathophysiology of atherosclerosis in vitro & ex vivo

•Investigate the mechanisms of atherosclerotic plaque disruption

•Examine the direct effect of different anti-atherosclerotic drugs on lesions

•Use …

Methods And Systems For Self-Organizing Non-Stationary Balloon Mesh Free Space Optical Networks, Muhammad Baig Awan

Theses and Dissertations

The Free Space Optical Networks are characterized by dynamic performance of optical wireless links as well as the atmospheric conditions and the mobility of free space optical nodes. In this dissertation, we focus on how to enhance the performance of free space optical network due to the mobility of free space optical nodes. The objective is to define and evaluate algorithms to establish continuous free space optical links in a stratospheric balloon mesh network. The main resource is the optical transceiver, which can be tuned to only one wavelength. Considering the constraint of single wavelength per transceiver, the wavelengths must …

Effect Of Plasma Dynamics On Gallium Nitride Nanorod And Growth By Molecular Beam Epitaxy, Dever Paul Norman

Theses and Dissertations

GaN is a wide bandgap semiconductor known for its use in high-frequency switching electronics and laser diodes, its stability as a high-temperature transistor material, and a radiation resistance which makes it an ideal material for space applications. Additionally, the discovery of the bandgap tunability of nitride materials using GaN has led to successful development of adjustable wavelength LED devices. However, the success of devices far outpaces the understanding of their material growth, making advances difficult to build upon. Plasma- Assisted Molecular Beam Epitaxy (PA-MBE) is an ideal growth method for achieving very precise structures for detailed study. Although plasma itself …

Controlling And Monitoring Voice Quality In Internet Communication, An Thanh Le

USF Tampa Graduate Theses and Dissertations

The Voice over Internet Protocol (VoIP) is on its way to surpassing toll quality. Although VoIP shares its transmission channel with other communication traffic, today internet has a wider bandwidth than the legacy Digital Loop Carrier and voice could be digitized higher than traditional 8 kbps, to say 16 kbps. Thus, VoIP should not be limited by the toll quality. However, VoIP quality could go down, as a result of unpredictable traffic congestion and network imperfections. These two situations cause delay jitter and packet loss of VoIP. To overcome these challenges, there are ongoing works for service providers including but …

Application Of Neural Networks To Acoustic Localization, Stephen Cronin

Doctoral Dissertations and Master's Theses

The intent of the work conducted was to build a neural network for the purposes of acoustic localization. The target of this localization is a sound source underwater. For our purposes, it is an acoustic pinger, as it produces consistent sound at a fixed rate making it ideal for testing. The network was intended to ingest raw data streams and output location information based on the arrangement of sensors employed. To achieve an accurate network, a simulation factoring in the environment was to be created to produce a data set large and diverse enough to describe the unique parameters of …

Evaluating The Impact Of Different Types Of Stabilized Bases On The Overall Performance Of Flexible Pavements, Andrae Anthony Francois

Theses and Dissertations

This study was initiated with the aim of evaluating the impact of stabilized and untreated base layers on the performance (i.e., fatigue and rutting) of flexible pavements. Four field sections constructed using stabilized base layers (i.e., bituminous (asphalt emulsion), calcium chloride (CaCl-2), Portland cement, and geogrid stabilized base layers) and a control section constructed using untreated RAP aggregates were analyzed in this study. Falling Weight Deflectometer (FWD) tests were conducted on all the field sections and the collected data was used to backcalculate the elastic moduli for all layers. The influence of the stabilized bases and the untreated RAP base …

Chemical And Physical Priming Of Human Mesenchymal Stem Cells To Alter Nonviral Gene Delivery Outcomes, Tyler Kozisek, Andrew Hamann, Amy Mantz, Mathias Schubert, Eva Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Human Mesenchymal Stem Cells: Human mesenchymal stem cells (hMSCs) are a multipotent cell, meaning they are able to differentiate into a more mature cell type, such as osteocytes, chondrocytes, and adipocytes, that are found in numerous tissues in the human body, such as bone marrow, fat, and muscle. Since hMSCs can be derived from adult human tissues, they do not have the same ethical concern associated with them as other stem cells, such as embryonic stem cells. Due to hMSCs multipotency and ease of obtaining, they have become one of the most widely researched stem cell types in areas such …

Optimal Control For Wind Turbine System Via State-Space Method, Mudhafar Lazam Shanoob

Theses and Dissertations

Renewable energy is becoming a fascinating research interest in future energy production because it is green and does not pollute nature. Wind energy is an excellent example of renewable resources that are evolving. Throughout the history of humanity, wind energy has been used. In ancient time, it was used to grind seeds, sailing etc. Nowadays, wind energy has been used to generate electrical power. Researchers have done a lot of research about using a wind source to generate electricity. As wind flow is not reliable, there is a challenge to get stable electricity out of this varying wind. This problem …

Application Of Ground Penetrating Radar To Highway-Related Problems, Rauf Rejab Hussein

Theses and Dissertations

The Broadway Bridge, constructed in 1923, crosses the Arkansas River in the downtown area of Little Rock, AR and was the main crossing point between Little Rock and North Little Rock. The structural deterioration of the bridge reached a level beyond patch and repair. Accordingly, the Arkansas Highway and Transportation Department (AHTD), in collaboration with the City of Little Rock, allocated the required resources ($98.4M) to demolish and replace the bridge. Due to the age of the bridge site and the limited knowledge of the subsurface utility layout, it became clear that geotechnical work be done in order to map …

Design And Experiments Of A Sic Power Mosfet-Based Bidirectional Switching Power Pole (Bspp), Hussain Khthear Sayed Subhii

Theses and Dissertations

This research presents the design and experiments of a SiC power MOSFET-based bidirectional switching power pole (BSPP) by benefiting from the advantages of SiC power MOSFETs: high-speed switching, high power density, high operating temperatures, and low power losses. The main goal of this research is to design a printed circuit board (PCB) prototype with a minimum parasitic inductance to improve the switching transient performance of the SiC MOSFETs for the BSPP application. The effects of the parasitic inductance of the PCB power traces were investigated, for the BSPP application, based on the experimental, simulation, and theoretical analyses. The PCB prototypes …

Project Halon: Engaging Secondary Students In High-Altitude Ballooning Experiments, James M. Taylor Jr., Derrick A. Nero

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Project HALON Overview

•Fewer US STEM graduates

•Shortage of STEM educators

•Lack of engaging, high quality STEM material in the classroom

•Potentially results in lower global economic competitiveness

Experiment Constraints

•Project brings together STEM major mentors and educators

•Builds understanding of research and operational challenges

•Students get excited about more complex experiments (CubeSATs)

HALON: High Altitude Learning Over Nebraska

•High altitude balloon lift platform

•Student-designed experiments tailored to student team abilities

•NASA-inspired near-space systems engineering process for tradeoffs

•Engagement / mentoring for pre-service and in-service educators

Investigation Of Synthetic Spider Silk Crystallinity And Alignment Via Electrothermal, Pyroelectric, Literature Xrd, And Tensile Techniques, Troy Munro, Tristan Putzeys, Michael Wubbenhorst, Christ Glorieux, Cameron G. Copeland, Randolph V. Lewis, Changhu Xing, Heng Ban

Faculty Publications

The processes used to create synthetic spider silk greatly affect the properties of the produced fibers. This paper investigates the effect of process variations during artificial spinning on the thermal and mechanical properties of the produced silk. Property values are also compared to the ones of the natural dragline silk of the N. clavipes spider, and to unprocessed (as-spun) synthetic silk. Structural characterization by scanning pyroelectric microscopy is employed to provide insight into the axial orientation of the crystalline regions of the fiber and is supported by XRD data. The results show that stretching and passage through liquid baths induce …

An Ir And Rf Based System For Functional Gait Analysis In A Multi-Resident Smart-Home, Erich Reinhardt Schafermeyer

Dissertations and Theses

Changes in the gait characteristics, such as walking speed and stride length, of a person living at home can be used to presage cognitive decline, predict fall potential, monitor long-term changes in cognitive impairment, test drug regimens, and more. This thesis presents a novel approach to gait analysis in a smart-home environment by leveraging new advances in inexpensive sensors and embedded systems to create novel solutions for in-home gait analysis. Using a simple, non-invasive hardware system consisting entirely of wall-mounted infrared and radio frequency sensor arrays, data is collected on the gait of subjects as they pass by. This data …

The Sustainability Of Ion Exchange Water Treatment Technology, Adib Amini

USF Tampa Graduate Theses and Dissertations

This research investigated using a life cycle environmental and economic approach to evaluate IX technology for small potable water systems, allowing for the identification and development of process and design improvements that reduce environmental impacts and costs. The main goals were to evaluate conventional IX in terms of life cycle environmental and economic sustainability, develop a method for improving designs of IX systems from a environmental and economic sustainability standpoint, evaluate potential design improvements, and make the research findings accessible to water professionals through user-friendly tools and frameworks that take into account their feedback. This research provides an understanding, from …

Technology Assessment Model Of Developing Geothermal Energy Resources For Supporting Electrical System: The Case For Oregon, Ahmed Shehab Alshareef

Dissertations and Theses

The demand for energy is increasing worldwide. All applications contributed to increase the demand of all energy industry, and therefore the effect on the environment and the rise in pollution increased significantly. This is considered a large problem, and researchers focused their research on renewable energy for reducing the cost of energy in the future. Geothermal energy has significant impact as a source of electricity generation since it will not harm the environment. There are more than twenty countries that benefit from geothermal plants, which generate more than 6000 megawatts .Three alternatives of geothermal energy technology (GHP, Direct use of …

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …

Use Of Chemical And Isotopic Identifiers To Characterize Ground Water Contamination Near Two Uranium Mill Sites, Central Nm, Mitchell T. Schatz

Civil Engineering ETDs

Chemical and isotopic signatures were used to discriminate between anthropogenic ground water and naturally occurring constituents. The U-234/U-238 activity ratio (AR) was determined in 34 samples from several aquifers underlying two former uranium mills near Milan, NM. Disposal of uranium ore waste into unlined tailings resulted in ground water contamination in the Lower San Mateo Creek Basin area. Ground water contamination from uranium mills have impacted the local ground water for residents down-gradient from the mills.

Previous studies that used uranium isotopes identified activity ratios of mill-derived uranium were near the secular equilibrium of 1, and those from natural ground …

Molecular-Size Selective Zeolite Membrane Encapsulated Novel Catalysts For Enhanced Biomass To Liquid (Btl) Processes, Ummuhan Cimenler

USF Tampa Graduate Theses and Dissertations

80% of energy usage in the word comes from fossil fuels (coal, oil, natural gas) and among the fossil fuels, oil is the most consumed energy source especially in transportation. However, due to concerns about energy demand and energy sustainability, global warming and dependency on foreign oil, generation of renewable fuels is crucial for transportation. Biomass to Liquid (BTL) is a promising process available to produce renewable liquid fuels. BTL fuels have great potential to meet the growing demand for liquid fuels, mitigating climate change, and providing value to rural areas. However, there are two major challenges with biofuels produced …

Strategies For Reducing Preventable Hospital Readmissions On Medicare Patients, Andres Patricio Garcia-Arce

USF Tampa Graduate Theses and Dissertations

The high expenditure of healthcare in the United States (U.S.) does not translate into better quality of care. Indeed, the U.S. healthcare system is recognized by its lack of efficiency and waste (which represents about 20% of the country’s healthcare expenses). Lack of coordination is one of the most referenced causes of waste in the U.S. healthcare system, and preventable hospital readmissions have been acknowledged to be evidence of poor coordination of care. In fiscal year 2013, the Centers for Medicare and Medicaid Services (CMS) established financial penalties for inpatient care reimbursements in hospitals with excessive readmissions. All the same, …

A Drosophila Model To Examine Collective Migration During Retinogenesis, Caroline Pena, Stephanie Zhang, Mildred Kamara, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

Retinal dysfunction is often caused by aberrant neural cell migration during development. In this study, we observed the migration of neural cells of the Drosophila melanogaster after marking cells of the 3rd instar larvae with the GAL4-UAS expression system when exposed to a concentration gradient of FGF-8 through the use of a microfluidic device. The glial and neuronal cell ratio in the developing brain was determined through immunofluorescent staining and observation. In future studies, a microfluidic device that mimics the developing Drosophila brain and retina will be designed in order to better understand the biological factors that affect the migration …

Propagating Degrees Of Truth On An Argumentation Framework: An Abstract Account Of Fuzzy Argumentation, Pierpaolo Dondio

Conference papers

This paper proposes a computational framework to reason with conflicting and gradual evidence. The framework is a synthesis of Dung’s seminal work in argumentation semantics with multi-valued logic. Abstract grounded semantics is used to identify the conditions under which a conclusion can be accepted, while multi-valued logic operators are used to quantify the degree of truth of such conditions. We propose a truth-compositional recursive computation based on the notion of irrelevant arguments, and we discuss examples using the major multi-valued logics: Godel’s, Zadeh’s and Łukasiewicz's logic.

An Approach To Robust Homing With Stereovision, Fuqiang Fu, Damian Lyons

Faculty Publications

Visual Homing is a bioinspired approach to robot navigation which can be fast and uses few assumptions. However, visual homing in a cluttered and unstructured outdoor environment offers several challenges to homing methods that have been developed for primarily indoor environments. One issue is that any current image during homing may be tilted with respect to the home image. The second is that moving through a cluttered scene during homing may cause obstacles to interfere between the home scene and location and the current scene and location. In this paper, we introduce a robust method to improve a previous developed …

The Design And Optimization Of Cooperative Mobile Edge, Xueqing Huang

Dissertations

As the world is charging towards the Internet of Things (IoT) era, an enormous amount of sensors will be rapidly empowered with internet connectivity. Besides the fact that the end devices are getting more diverse, some of them are also becoming more powerful, such that they can function as standalone mobile computing units with multiple wireless network interfaces. At the network end, various facilities are also pushed to the mobile edge to foster internet connections. Distributed small scale cloud resources and green energy harvesters can be directly attached to the deployed heterogeneous base stations.

Different from the traditional wireless access …

Forensic Research On Detecting Seam Carving In Digital Images, Jingyu Ye

Dissertations

Digital images have been playing an important role in our daily life for the last several decades. Naturally, image editing technologies have been tremendously developed due to the increasing demands. As a result, digital images can be easily manipulated on a personal computer or even a cellphone for many purposes nowadays, so that the authenticity of digital images becomes an important issue. In this dissertation research, four machine learning based forensic methods are presented to detect one of the popular image editing techniques, called ‘seam carving’.

To reveal seam carving applied to uncompressed images from the perspective of energy distribution …

Design And Optimization Of An Explosive Storage Policy In Internet Fulfillment Warehouses, Sevilay Onal

Dissertations

This research investigates the warehousing operations of internet retailers. The primary physical process in internet retail is fulfillment, which typically involves a large internet fulfillment warehouse (IFW) that has been built and designed exclusively for online sales and an accompanying parcel delivery network. Based on observational studies of IFW operations at a leading internet retailer, the investigations find that traditional warehousing methods are being replaced by new methods which better leverage information technology and efficiently serve the new internet retail driven supply chain economy. Traditional methods assume a warehouse moves bulk volumes to retail points where the bulks get broken …