Engineering Commons^™

Improving Early-Age Cracking Resilience And Durability Of Concrete Elements, Ananya Markandeya

USF Tampa Graduate Theses and Dissertations

Control of early-age cracking in concrete structures due to restrained deformation, thermal and/or autogenous, presents a major durability challenge for state highway agencies. This study details research conducted on improving the early-age cracking resilience of plain concrete and supplementary cementitious materials (SCM) blended concrete. Three specific areas, within concrete structural elements, with high incidence of early-age cracking are addressed:

• High early-age strength (HES) concrete mixtures used in slab-replacement of Jointed Plain Concrete Pavements (JPCP)
• Use of metakaolin (MK) in bridge deck mixtures
• Use of slag blended concrete, at high cement replacement levels, in massive structural elements

Three cracking mitigation measures …

Materials And Methods To Fabricate Porous Structures Using Additive Manufacturing Techniques, Mohsen Ziaee

USF Tampa Graduate Theses and Dissertations

Additive Manufacturing (AM), as the name implies, produces three-dimensional objects by progressively adding material rather than cutting away unneeded material. Typically this is done by processing a series of cross-sections obtained from a Computer Aided Design (CAD) model of the object. AM systems can process liquid photopolymers and solid materials in form of powder, wire and laminates to create intricate geometries in a short lead time.

This superb capability of AM methods enables to locally suit the properties of the part for the desired function by incorporating the designed pores in the CAD model [2]. The pore gradient creation opens …

A Study On The Adaptability Of Immune System Principles To Wireless Sensor Network And Iot Security, Vishwa Alaparthy

USF Tampa Graduate Theses and Dissertations

Network security has always been an area of priority and extensive research. Recent years have seen a considerable growth in experimentation with biologically inspired techniques. This is a consequence of our increased understanding of living systems and the application of that understanding to machines and software. The mounting complexity of telecommunications networks and the need for increasing levels of security have been the driving factor. The human body can act as a great role model for its unique abilities in protecting itself from external, foreign entities. Many abnormalities in the human body are similar to that of the attacks in …

Enhancement Of Rainfall-Triggered Shallow Landslide Hazard Assessment At Regional And Site Scales Using Remote Sensing And Slope Stability Analysis Coupled With Infiltration Modeling, Thilanki Maneesha Dahigamuwa Rajaguru Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Landslides cause significant damage to property and human lives throughout the world. Rainfall is the most common triggering factor for the occurrence of landslides. This dissertation presents two novel methodologies for assessment of rainfall-triggered shallow landslide hazard. The first method focuses on using remotely sensed soil moisture and soil surface properties in developing a framework for real-time regional scale landslide hazard assessment while the second method is a deterministic approach to landslide hazard assessment of the specific sites identified during first assessment. In the latter approach, landslide inducing transient seepage in soil during rainfall and its effect on slope stability …

Wastewater In Context: Systems-Based Approaches To Improving Wastewater Infrastructure Transitions, Christine Prouty

USF Tampa Graduate Theses and Dissertations

Coastal communities and ecosystems around the world are some of those most vulnerable to the impacts of climate change. In particular, the wastewater treatment systems in these areas are on the forefront of the effects of increasing frequency, duration, and intensity associated with extreme weather events. As such, decision making about adopting new wastewater technologies or transitioning to an improved treatment portfolio is an important area of research for coastal communities because they are critically linked to the health of the nearby aquatic ecosystems (i.e. tourism, fishing, cultural heritage, climate protection).

The decision making process about technology adoption and transitions …

Aqueous Humor Dynamics And The Constant-Pressure Perfusion Model Of Experimental Glaucoma In Brown-Norway Rats, Kayla R. Ficarrotta

USF Tampa Graduate Theses and Dissertations

Glaucoma affects tens of millions of people and is the leading cause of irreversible blindness worldwide. Virtually all current glaucoma therapies target elevated intraocular pressure (IOP); however, the contribution of intracranial pressure (ICP) to glaucoma has recently garnered interest. Strain at the optic nerve head is now known to depend on the translaminar pressure difference (TLPD), which is the difference between IOP and ICP, rather than IOP alone. A better understanding of how IOP and ICP relate to glaucoma development and progression is essential for developing improved therapies and diagnostic tests. Glaucoma is commonly modeled in rats, yet aqueous humor …

Analysis Of Printed Electronic Adhesion, Electrical, Mechanical, And Thermal Performance For Resilient Hybrid Electronics, Clayton Neff

USF Tampa Graduate Theses and Dissertations

Today’s state of the art additive manufacturing (AM) systems have the ability to fabricate multi-material devices with novel capabilities that were previously constrained by traditional manufacturing. AM machines fuse or deposit material in an additive fashion only where necessary, thus unlocking advantages of mass customization, no part-specific tooling, near arbitrary geometric complexity, and reduced lead times and cost. The combination of conductive ink micro-dispensing AM process with hybrid manufacturing processes including: laser machining, CNC machining, and pick & place enables the fabrication of printed electronics. Printed electronics exploit the integration of AM with hybrid processes and allow embedded and/or conformal …

Multilayer Dielectric Rod Waveguide And Dielectric Rod Antenna With Enhanced Performance, Denise C. Lugo

USF Tampa Graduate Theses and Dissertations

This dissertation presents first a comprehensive study of the design and performance of a multilayer dielectric rod waveguide (DRW) with rectangular cross-section. The design is comprised of a high permittivity core encased by a low permittivity cladding. A modal analysis of the multilayer DRW with a 2:1 core aspect ratio is presented and a mathematical model is proposed to characterize the fundamental mode cutoff frequency in terms of the core and cladding permittivity and the core dimensions. The explicit nature of the model is useful for design and it offers an excellent match to the full-wave EM simulation data. The …

Demonstration Of Monolithic-Silicon Carbide (Sic) Neural Devices, Evans K. Bernardin

USF Tampa Graduate Theses and Dissertations

Brain Machine Interfaces (BMI) provide a communication pathway between the electrical conducting units of the brain (neurons) and external devices. BMI technology may provide improved neurological and physiological functions to patients suffering from disabilities due to damaged nervous systems. Unfortunately, microelectrodes used in Intracortical Neural Interfaces (INI), a subset of the BMI device family, have yet to demonstrate long-term in vivo performance due to material, mechanical and electrical failures. Many state-of-the-art INI devices are constructed using stacks of multiple materials, such as silicon (Si), titanium (Ti), platinum (Pt), parylene C, and polyimide. Not only must each material tolerate the biological …

Heart Rate Variability Analysis As A Means Of Real-Time Hypercapnia Detection, Joseph Dituri

USF Tampa Graduate Theses and Dissertations

The motivation for this research is the high prevalence experienced by divers of carbon dioxide (CO₂) issues and concerns throughout their lives. Additionally, CO₂ is naturally occurring, the product of oxidative metabolism, and is undetectable to human senses. Current CO₂ sensor or detection technology is limited to high-cost machines such as arterial blood gas monitors and end tidal CO₂ monitors, or more modern technology relying upon bright lights which measure blood flow. The light technology is notoriously unreliable and does not produce a very effective heart beat allowing a user to detect minimal changes. Heart …

A Theoretical And Practical Analysis Of The Effect Of Drilling Fluid On Rebar Bond Strength, Kelly Costello

USF Tampa Graduate Theses and Dissertations

Drilled shafts are large cylindrical cast-in-place concrete structural elements that can be favored due to cost-effectiveness. These elements however, require strict quality control during construction to ensure a stable excavation. Drilling fluid is often used in construction to attain this stability. Drilling fluid, or slurry, can be ground water or salt water, but is typically made from a mixture of water and mineral or polymer powder to form a viscous fluid slightly more dense than ground water. During concreting, the drilling fluid is displaced by the heavier concrete, which is tremie placed at the base of the excavation from the …

The Icarus Floating Membrane Photobioreactor For Microalgae Cultivation In Wastewater: Advancing Technology From Lab To Field Prototype, Melanie Pickett

USF Tampa Graduate Theses and Dissertations

The ICARUS membrane photobioreactor, conceptualized and preliminarily tested at the University of South Florida, provides a viable platform for algae cultivation using wastewater as a growth medium. Progression of the technology is tracked using NASA’s Technology Readiness Level scale, and is herein described. Through the work described in this manuscript, the technology has evolved from TRL 3 to TRL 5. Completing the suggested future work will readily move the technology to TRL 6 and beyond.

The first study investigated the co-location of algal cultivation with wastewater treatment. This coupling provides a steady source of water and nutrients for algal growth. …

Simulation And Optimization Of A Sheathless Size-Based Acoustic Particle Separator, Shivaraman Asoda

USF Tampa Graduate Theses and Dissertations

Standing surface acoustic waves (SSAW) have been widely used for sorting of cells and particles. However, the major challenges faced with the acoustic driven separation process is the need for an optimized setup to achieve effective separation and the range of particles that can be separated. In this thesis, a custom simulation model is studied to investigate and optimize the separation of varying size particles in a sheathless acoustic separation platform that was developed in our research lab. Specifically, the effect of flowrate, pressure amplitude, wavelength and interdigitated transducers (IDTs) physical parameters on the separation efficiency is explored. We also …

Control Of Uncertain Dynamical Systems With Spatial And Temporal Constraints, Ehsan Arabi

USF Tampa Graduate Theses and Dissertations

The overarching objective of this dissertation is the development of feedback control frameworks for uncertain dynamical systems that are subject to spatial and/or temporal constraints. These spatiotemporal constraints usually arise from the physical and/or performance characteristics associated with a considered dynamical system in safety-critical applications, where synthesis and analysis of feedback control laws are not trivial. Specifically, the proposed control architectures in this dissertation mainly contribute to the model reference adaptive control and finite-time control literature. In particular, unlike existing model reference adaptive control approaches that are not capable of enforcing user-defined performance guarantees without an ad-hoc tuning process, the …

On The Feasibility Of Profiling, Forecasting And Authenticating Internet Usage Based On Privacy Preserving Netflow Logs, Soheil Sarmadi

USF Tampa Graduate Theses and Dissertations

Understanding Internet user behavior and Internet usage patterns is fundamental in developing future access networks and services that meet technical as well as Internet user needs. User behavior is routinely studied and measured, but with different methods depending on the research discipline of the investigator, and these disciplines rarely cross. We tackle this challenge by developing frameworks that the Internet usage statistics used as the main features in understanding Internet user behaviors, with the purpose of finding a complete picture of the user behavior and working towards a unified analysis methodology. In this dissertation we collected Internet usage statistics via …

An Analytical Solution For Attainment Of Field Capacity, Ali Aldrees

USF Tampa Graduate Theses and Dissertations

Field Capacity (FC) is a key parameter to quantify in agricultural engineering, irrigation controlling, and soil physics studies. For instance, irrigation studies focuses on determining the optimal amount of water needed by plants to grow following an irrigation system and therefore relies on determining FC. Likewise, the value of FC is a good indicator of soil textures, structures and pore size distributions. For example, loamy soils have a wider distribution of pores leading to high FC values. FC depends on multiple physically-grounded variables which include matric potential value (ψ_FC ), water content at FC (θ_FC ), specific drainage time to …

A Cost Benefit Analysis Of Using A Battery Energy Storage System (Bess) Represented By A Unit Commitment Model, Nemanja Mihailovic

USF Tampa Graduate Theses and Dissertations

This thesis aims to provide a general overview of a cost and benefit analysis of incorporating a battery energy storage system within unit commitment model.

The deregulation of the electricity market in the U.S. has only been around for the last two decades. With renewable energy and energy storage systems becoming less expensive, a decentralized market scheme is becoming more popular and plausible. The scope of this work is to provide a fundamental understanding of unit commitment and a cost analysis of applying a battery energy storage system to an already established power system.

A battery energy storage system (BESS) …

Acoustic Source Localization With A Vtol Suav Deployable Module, Kory Olney

USF Tampa Graduate Theses and Dissertations

A real time acoustic direction-finding module has been developed to estimate the ele- vation and azimuth of an impulsive event while function aboard a small unmanned air- craft vehicle. The generalized cross-correlation with phase transform method was used to estimate time differences of arrival in an 8 channel microphone array. A linear least squares approach was used to calculate an estimate for the direction of arrival. In order to accomplish this task, a vertical takeoff and landing small unmanned aircraft system was assembled to host the direction finding module. The module itself is made up of an eight-channel synchronous analog-to-digital …

Enhanced Co2 Conversion By The Simultaneous Doping Of Co, Fe, And Mn In The B-Site Of A Lanthanum Perovskite, Adela E. Ramos

USF Tampa Graduate Theses and Dissertations

There is a pressing need for carbon dioxide (CO₂) mitigation technologies as increasing emissions continue to threaten our environment. Carbon capture and storage (CCS) alone would not be able to achieve temperature rise below 2 °C. In addition, CCS cost increases considerably for power generation and other industries where CO₂ separation is necessary. Conversion of CO₂ to usable products is the most economical and feasible solution as it could offset CO₂ separation cost. Liquid fuels are an attractive route since it is a commodity used globally and demand increases with population and economic growth. Conversion …

Comparison Of Bacterial And Viral Reduction Across Different Wastewater Treatment Processes, Aayushi R. Vagadia

USF Tampa Graduate Theses and Dissertations

Today billions of people live without access to basic sanitation facilities, and thousands die every week due to diseases caused by fecal contamination associated with improper sanitation. It has thus become crucial for decision makers to have access to relevant and sufficient data to implement appropriate solutions to these problems. The Global Water Pathogen Project http://www.waterpathogens.org/ is dedicated to providing an up-to-date source of data on pathogen reduction associated with different sanitation technologies that are important if the world is to achieve the Sustainable Development Goals (SDGs) related to health and sanitation provision. In this research, a subset of the …

Sorption Of Benzene, Toluene And Ethylbenzene By Plasticized Poly (Ethyl Methacrylate) Using Quartz Crystal Microbalance At 298.15k, Kiranpreet Kaur

USF Tampa Graduate Theses and Dissertations

Quartz crystal microbalances (QCM) are chemical sensors used for liquid and vapor sensing. In this thesis work, plasticized poly (ethyl methacrylate) (PEMA) coated QCM was used to study sorption behavior of benzene, ethylbenzene and toluene in respective polymer at 298.15K. Poly (ethyl methacrylate) (PEMA) is a promising polymer with solubility parameter close to BTEX compounds, but it's glassy and rigid nature at room temperature make it less sensitive. The addition of plasticizers (Diisononyl cyclohexane-1,2-dicarboxylate (DINCH) and Diisooctyl azelate (DIOA)) lowers the glass transition temperature, provides flexibility and thus increases the free volume of the polymer to enhance analyte sorption. In …

Validation Of Results Of Smart Grid Protection Through Self-Healing, Felipe Framil Assumpção

USF Tampa Graduate Theses and Dissertations

This is a verification of the results of “Smart Grid Protection through Self-Healing” from the publication of Chathurika Chandraratne, et al., that proposes a protection solution for the smart grid. The paper used as reference has as the main focus on three different protections; directional overcurrent protection, overcurrent protection, and transformer protection, which are validated through ETAP software simulation of IEEE- 9 bus and 14 bus electrical power systems, the same used by the author. It was validated after repeated simulation, that just as intended, self-healing increases system agility, and it helped prevent false-tripping14 bus electrical power systems.

Application Of A Floating Membrane Algal Photobioreactor For Freshwater Aquaculture, Hsiang-Yang Shyu

USF Tampa Graduate Theses and Dissertations

As the global population grows, water and food demand also increase. The intensive aquaculture industry has helped to mitigate these problems. In order to make aquaculture sustainable, it is necessary to remove the abundant nutrients produced by fish in the water. In this study, the role of the microalga of Chlorella vulgaris in the Isolated Cultivation of Algal Resources Utilizing Selectivity (ICARUS) membrane photobioreactor was evaluated for nutrient control in the aquaculture system. The production of algal biomass, the removal rate of nutrients, and the impact of microalgae on cultured organisms were monitored during the operation of aquaculture systems. At …

Statistical Monitoring Of Queuing Networks, Yaren Bilge Kaya

USF Tampa Graduate Theses and Dissertations

Queuing systems are important parts of our daily lives and to keep their operations at an efficient level they need to be monitored by using queuing Performance Metrics, such as average queue lengths and average waiting times. On the other hand queue lengths and waiting times are generally random variables and their distributions depend on different properties like arrival rates, service times, number of servers. We focused on detecting the change in service rates in this report. Therefore, we monitored queues by using Cumulative Sum(CUSUM) charts based on likelihood ratios and compared the Average Run Length values of different service …

Recovery Of Nutrients From Anaerobically Digested Enhanced Biological Phosphorus Removal (Ebpr) Sludge Through Struvite Precipitation, Maraida Balaguer-Barbosa

USF Tampa Graduate Theses and Dissertations

Water resources in Florida have been severely degraded by eutrophic conditions, resulting toxic algae blooms, which negatively affect health and tourism. Eutrophication, or excessive amount of phosphorus (P) and nitrogen (N) in water, overstimulates the production of aquatic plants, depletes dissolved oxygen, and deteriorates the aquatic environment. However, phosphorus is a non-renewable resource essential for all living organisms. In fact, more than half of the total demand for P globally is to supply the food industry, which has concerningly accelerated the depletion rates of phosphate reserves.

In many wastewater treatment plants (WWTPs), the enhanced biological phosphorus removal (EBPR) approach has …

Numerical Analysis Of Leakage Through Defective Geomembrane Liners In Embankment Dams, Sarper Demirdogen

USF Tampa Graduate Theses and Dissertations

Placing a geomembrane liner in the core of a dam is an alternative construction technique to traditional clay core types. This study aims to assess the performance of such internal geomembrane sealing systems in an earthen dam. Two-dimensional (2D) numerical analysis was performed to evaluate leakage through defective seams within an earthen dam. Five possible applications of internal geomembrane systems were initially modeled to locate the zero-pressure lines in an earthen dam. Then, another application where the geomembrane is placed on the upstream face was modeled to compare the upstream and internal geomembrane systems. The results of this study show …

Gate Level Probabilistic Simulation Based Hardware Trojan Susceptibility Analysis Of Combinational Circuits, Venkata Lakshmi Bhargavi Gurram

USF Tampa Graduate Theses and Dissertations

Today multi-million gate integrated circuits are being commonly used in many critical (eg., health care) and sensitive (eg., military) applications. Therefore, they are susceptible to malicious modifications, namely, Hardware Trojans (HTs), with the intent of leaking sensitive information, denial-of-service etc. There are many ways of inserting Hardware Trojans in ICs. Thus, HT detection and mitigation are very important tasks. In this thesis, we propose a novel probabilistic simulation based approach to estimate the susceptibility of a combinational circuit to a HT. One of the common ways is to simulate the netlist with typical input sequences and identifying low activity nets …

The Role Of Forests In Securing Hydropower Needs Of Cambodia, Mohit Kaura

USF Tampa Graduate Theses and Dissertations

Hydropower relies on protection of watersheds to regulate water and sediment yields. Deforestation accelerates the rate of soil erosion, thereby increasing the amount of river sediments heading to the dam's reservoir, decreasing the longevity of the dam. In Cambodia in particular, recent deforestation rates are among the largest on the planet, and forests are expected to disappear within the lifespan of proposed dams. The cost of protecting and restoring forested watersheds can be considered as an annual investment towards sustainable reservoir management and hydropower generation. A modeling framework is developed to estimate the sediment accumulation in reservoirs from deforestation-driven soil …

Effect Of Heating On Heat Capacity Of Vegetable Oils Used For Biofuel Production, Sailee Nitin Nagpurkar

USF Tampa Graduate Theses and Dissertations

Biodiesel has become a major renewable fuel for diesel engines particularly from various waste sources. New biodiesel production technologies are emerging with data demands for efficient process design. This project highlights the data requirements, gaps in the thermo-physical property data, and consolidation of experimental and estimation methods for effective process development. Knowing the thermodynamic properties of a substance is important in order to know what process or procedures it has to go under. The aim of this project is to assess the potential of vegetable oils to serve as feedstock for biofuel production by determining their heat capacity (Cp). Such …

A Comparative Study Of Signal Processing Methods For Fetal Phonocardiography Analysis, Venkata Akshay Bhargav Krishna Vadali

USF Tampa Graduate Theses and Dissertations

More than one million fetal deaths occur in the United States every year [1]. Monitoring the long-term heart rate variability provides a great amount of information about the fetal health condition which requires continuous monitoring of the fetal heart rate. All the existing technologies have either complex instrumentation or need a trained professional at all times or both. The existing technologies are proven to be impractical for continuous monitoring [2]. Hence, there is an increased interest towards noninvasive, continuous monitoring, and less expensive technologies like fetal phonocardiography.

Fetal Phonocardiography (FPCG) signal is obtained by placing an acoustic transducer on the …