Engineering Commons^™

Shortcut Nitrogen Removal In Photo-Sequencing Batch Reactor, Experiments, Dynamic Model And Full-Scale Design, Sahand Iman Shayan

USF Tampa Graduate Theses and Dissertations

Nitrogen is one of the essential elements for life; however, inefficient use of nitrogen creates major environmental problems. Nitrogen-rich streams from urban areas, farms, and wastewater treatment plants (WWTPs) lead to surface and groundwater contamination, resulting in eutrophication, hypoxia, and notable environmental, public health and economic damage. Ammonia is a form of nitrogen that can be created during industrial or biological nitrogen fixation or decomposition of biomass. Anaerobic digesters (ADs) in WWTP generate biogas from collected sludge from primary and secondary clarifiers to achieve energy recovery in the plant. However, sidestream effluent from dewatering AD sludge contains high concentrations of …

Low-Cost Device For Laser Phacoemulsification: A Preliminary Study, Mitchell Harrah

USF Tampa Graduate Theses and Dissertations

The current gold standard of cataract removal surgery is phacoemulsification systems. These are divided based on the type of devices used; both are considered equal but with different delivery modes. These delivery methods are either acoustic or light-based. However, these devices pose two hurdles for impoverished areas: high costs and heavy resource usage. This thesis proposes a novel phacoemulsification system is based on the low-cost, off-shelf laser diodes that implement light-based phacoemulsification of cataracts. The system is tested for viability over two methods: finite element analysis and experimentation on various phantoms. Simulations on the device have occurred on the COMSOL …

Testing And Packaging For Mems Acoustic Emission Sensors, Ting-Hung Liu

USF Tampa Graduate Theses and Dissertations

The goal of this research is to improve the structure and dimension of the MEMS acoustic emission sensor. Acoustic emission sensor (AE sensor) based on the piezoelectric transducer is a well-developed technology in non-destructive testing that is widely used to determine permanent damage such as cracks and corrosions in buildings and structures. The AE sensor can be used to monitor cracks in structures and to check leakage in pressurized systems. The location of cracks in a structure or system leakage causes a high-frequency surface vibration while releasing ultrasonic energy. The frequency of this energy is typically between 30 kHz to …

Development Mems Acoustic Emission Sensors, Adrian Enrique Avila Gomez

USF Tampa Graduate Theses and Dissertations

The purpose of this research is to develop MEMS based acoustic emission sensors for structural health monitoring. Acoustic emission (AE) is a well-established nondestructive testing technique that is typically used to monitor for fatigue cracks in structures, leaks in pressurized systems, damages in composite materials or impacts. This technology can offer a precise evaluation of structural conditions and allow identification of imminent failures or minor failures that can be addressed by planned maintenances routines. AE causes a burst of ultrasonic energy that is measured as high frequency surface vibrations (30 kHz to 1 MHz) generated by transient elastic waves that …

The Development Of A Prosthetic Training Software For Upper Limb Amputees, Tyler Kayne Sullins

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to develop an intuitive software that aids in the field of prosthetic training and rehabilitation by creating an individualized visualization of joint angles. This software is titled “the prosthetic training software (PTS) for individualized joint angle representation”, and it enables the individualized portrayal of predicted or pre-recorded joint angles. The PTS is an intuitive program for clinicians and prosthesis users that produces an animation of a virtual avatar reflecting the user’s segment lengths and amputation for rehabilitation and training purposes.

The PTS consists of a graphical user interface (GUI) and a 3D visualization of …

Enhancement Of Supercapacitor Energy Storage By Leakage Reduction And Electrode Modification, Tete Tevi

USF Tampa Graduate Theses and Dissertations

Supercapacitors have emerged in recent years as a promising energy storage technology. The main mechanism of energy storage is based on electrostatic separation of charges in a region at the electrode-electrolyte interface called double layer. Various electrode materials including carbon and conducting polymers have been used in supercapacitors. Also, supercapacitors offer high life cycle and high power density among electrochemical energy storage devices. Despite their interesting features, supercapacitors present some disadvantages that limit their competitivity with other storage devices in some applications. One of those drawbacks is high self-discharge or leakage. The leakage occurs when electrons cross the double layer …

Photonic Crystal-Based Flow Cytometry, Justin William Stewart

USF Tampa Graduate Theses and Dissertations

Photonic crystals serve as powerful building blocks for the development of lab-on-chip devices. Currently they are used for a wide range of miniaturized optical components such as extremely compact waveguides to refractive-index based optical sensors. Here we propose a new technique for analyzing and characterizing cells through the design of a micro-flow cytometer using photonic crystals. While lab scale flow cytometers have been critical to many developments in cellular biology they are not portable, difficult to use and relatively expensive. By making a miniature sensor capable of replicating the same functionality as the large scale units with photonic crystals, we …

Packet Coalescing And Server Substitution For Energy-Proportional Operation Of Network Links And Data Servers, Mehrgan Mostowfi

USF Tampa Graduate Theses and Dissertations

Electricity generation for Information and Communications Technology (ICT) contributes over 2% of the human-generated CO2 to the atmosphere. Energy costs are rapidly becoming the major operational expense for ICT and may soon dwarf capital expenses as software and hardware continue to drop in price. In this dissertation, three new approaches to achieving energy-proportional operation of network links and data servers are explored.

Ethernet is the dominant wireline communications technology for Internet connectivity. IEEE 802.3az Energy Efficient Ethernet (EEE) describes a Low Power Idle (LPI) mechanism for allowing Ethernet links to sleep. A method of coalescing packets to consolidate link idle …

A Methodology For Scheduling Operating Rooms Under Uncertainty, Marbelly Paola Davila

USF Tampa Graduate Theses and Dissertations

An operating room (OR) is considered to be one of the most costly functional areas within hospitals as well as its major profit center. It is known that managing an OR department is a challenging task, which requires the integration of many actors (e.g., patients, surgeons, nurses, technicians) who may have conflicting interests and priorities.

Considering these aspects, this dissertation focuses on developing a simulation based methodology for scheduling operating rooms under uncertainty, which reflects the complexity, uncertainty and variability associated with surgery.

We split the process of scheduling ORs under uncertainty into two main components. First, we designed a …

A Study On Lane-Change Recognition Using Support Vector Machine, Weiping Deng

USF Tampa Graduate Theses and Dissertations

This research focuses primary on recognition of lane-change behaviors using support vector machines (SVMs). Previous research and statistical results show that the vast majority of motor vehicle accidents are caused by driver behavior and errors. Therefore, the interpretation and evaluation of driver behavior is important for road safety analysis and improvement. The main limit to understanding driver behavior is the data availability. In particular, a full-scale lane-change data set is difficult to collect in a real traffic environment because of the safety and cost issues. Considering the data demands of the recognition model development and the obstacles of field data …

Analyses Of Variable Refrigerant Flow And Exergy In Air Conditioning Systems, Rashid Ali Alshatti

USF Tampa Graduate Theses and Dissertations

This thesis consists of two research problems in the air conditioning (A/C) area. For the first problem, the aim is to model and simulate a variable refrigerant flow (VRF) air conditioning system. The coefficient of performance (COP) for refrigeration or heat pump system is one of the critical parameters for designing an air conditioning system. The modeling of the system components for a VRF cycle under different cooling conditions using R-134a and R-22 as refrigerants was carried out. Calculations were performed by varying different parameters such as condenser and evaporator temperatures, and refrigerant type. The R-134a refrigerant shows a better …

Asymmetric Passive Dynamic Walker Used To Examine Gait Rehabilitation Methods, John Sushko

USF Tampa Graduate Theses and Dissertations

Testing gait rehabilitation devices on humans can be a difficult task, due to the effects of the neurological controls of the human body. This thesis advances the use of a passive dynamic walker (PDW) tuned to have asymmetric gait patterns similar to those with physical impairments to test rehabilitation devices. A passive dynamic walker is a multipendulum system that has a stable gait pattern when walking down a slope without any energy inputs except the forces due to gravity. A PDW model is better suited for testing rehabilitation devices because it has been shown to resemble human gait and separates …

Operational Performance Evaluation Of Four Types Of Exit Ramps On Florida's Freeways, Linjun Lu

USF Tampa Graduate Theses and Dissertations

This research focuses primarily on the analysis of exit ramp performance related to safety and operations. The safety analysis focuses on the impacts of different exit ramp types for freeway diverge areas and different factors contributing to the crashes that occur on the exit ramp sections. The operational analysis is based mainly on simulations by TSIS-CORSIM. Different ramp effects and guidance for selecting optimal exit ramp type are concluded. Issues related to ramp sections and crossroad sections are also demonstrated. Minimum ramp length and minimum distance between ramp terminal and downstream or upstream intersections are calculated. The operational analysis was …

Gate Level Dynamic Energy Estimation In Asynchronous Circuits Using Petri Nets, Ryan Mabry

USF Tampa Graduate Theses and Dissertations

This thesis introduces a new methodology for energy estimation in asynchronous circuits. Unlike existing probabilistic methods, this is the first simulative work for energy estimation in all types of asynchronous circuits.

The new simulative methodology is based on Petri net modeling. A real delay model is incorporated to capture both gate delays and interconnect delays. The switching activity at each gate is captured to measure the average dynamic energy consumed per request/acknowledge handshaking pair. The new type of Petri net is called Hierarchical Colored Asynchronous Hardware Petri net (HCAHPN). The HCAHPN is able to capture the temporal and spatial correlations …

Physical-Statistical Modeling And Optimization Of Cardiovascular Systems, Dongping Du

USF Tampa Graduate Theses and Dissertations

Heart disease remains the No.1 leading cause of death in U.S. and in the world. To improve cardiac care services, there is an urgent need of developing early diagnosis of heart diseases and optimal intervention strategies. As such, it calls upon a better understanding of the pathology of heart diseases.

Computer simulation and modeling have been widely applied to overcome many practical and ethical limitations in in-vivo, ex-vivo, and whole-animal experiments. Computer experiments provide physiologists and cardiologists an indispensable tool to characterize, model and analyze cardiac function both in healthy and in diseased heart. Most importantly, simulation modeling empowers the …