Engineering Commons^™

Design And Control Of A Bidirectional Dual Active Bridge Dc-Dc Converter To Interface Solar, Battery Storage, And Grid-Tied Inverters, Kenny George

Electrical Engineering Undergraduate Honors Theses

In order to further reduce the size of today’s power converters, wide bandgap semiconductor technologies are being explored. These devices, such as silicon carbide (SiC), have been shown to outperform their silicon counterparts when used in high frequency switching, high temperature, and high voltage applications. These properties make them highly desirable in the bidirectional dual active bridge power converter. Being an isolated converter topology, the dual active bridge employs a transformer to provide step-up/step-down functionality and galvanic isolation for the converter. Transformers, as well as other passive components such as inductors and capacitors may be reduced in size when higher …

Design And Development Of A Wearable Wireless Health Monitoring System: A Smart Watch Approach, Keerthi Paranikumar

Graduate Theses and Dissertations

According to Statistics, every year, about 610,000 people die because of heart disease in United States of America. (i.e. 1 in every 4 deaths.*) Heart disease is common for both men and women. Annually, about 370,000 people die because of coronary heart disease, which is the most common type of heart disease [1]. About 735,000 Americans have heart attack every year. In this, 210,000 people gets heart attack who already has heart problems and 525,000 people get heart attack for the first time [2]. Not many people know that they have heart problems. Around 47% of the people in United …

Epitaxial Growth Of Si-Ge-Sn Alloys For Optoelectronic Device Application, Aboozar Mosleh

Graduate Theses and Dissertations

Microelectronics industry has experienced a tremendous change over the last few decades and has shown that Moore’s law has been followed by doubling the number of transistors on the chip every 18 months. However, continuous scaling down of the transistors size is reaching the physical limits and data transfer through metal interconnects will not be able to catch up with the increasing data processing speed in the future. Therefore, optical data transfer between chips and on-chip has been widely investigated. Silicon based optoelectronics has received phenomenal attention since Si has been the core material on which microelectronic industry has been …

Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar

Graduate Theses and Dissertations

Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …

Image Processing And Visualization Of Terahertz Pulsed Imaging Of Breast Cancer Tumors, Yuhao Wu

Graduate Theses and Dissertations

Terahertz imaging technology has grown substantially in recent years. With new advances made in the generation, manipulation, and detection of terahertz radiation, terahertz imaging has found its application as inspection tools in a wide range of areas including biomedicine, materials science, and aerospace industries. In the field of medical imaging, terahertz (THz) has emerged as a new imaging modality due to some fundamental physical properties of the THz wave. THz imaging has been used to examine various biological structures, and THz tomography has been developed to probe the 3D structures of those samples.

THz pulsed imaging (TPI) is one of …

Industrial Energy Consumption, Benchmarking, And Analysis In The United States, Daniel Maldonado

Mechanical Engineering Undergraduate Honors Theses

The purpose of this paper is to analyze the energy consumption of the industrial sector in the United States, and to identify the tools that can be used to minimize the consumption and improve the energy efficiency of all facilities in the country. The first part of the paper is a historical analysis of the industrial sector energy consumption, where the different energy sources are identified. The second part details different electronic tools that will provide facilities the ability of performing benchmarking, in order to understand their energy performance. Finally, the third part of this paper provides information about the …

Eeg-Controlling Robotic Car And Alphabetic Display By Support Vector Machine For Aiding Amyotrophic Lateral Sclerosis Patients, Quang M. Le

Electrical Engineering Undergraduate Honors Theses

This thesis presents the design and experiment of a system that can detect the human thinking such as driving directions and letters using the brainwave signals known as electroencephalogram (EEG) and a machine learning algorithm called support vector machine (SVM). This research is motivated by amyotrophic lateral sclerosis (ALS) disease which makes patients seriously lose mobility and speaking capabilities. The developed system in this thesis has three main steps. First, wearing EPOC headset from Emotiv Company, a user can record the EEG signals when he/she is thinking a direction or a letter, and also save the data in a personal …

Model Development And Validation For Wind Generation Transmission Systems, Mahmood Shihadeh Saadeh

Graduate Theses and Dissertations

In this research a new benchmark system is proposed for wind energy transmission systems. New model development, validation, and calibration methods for power transmission systems are proposed and implemented as well. First, a model reduction criteria is chosen based on electrical interconnection and geographical information. Model development is then done using reduction techniques on an operation model provided by a transmission operator based on the chosen criteria. Then model validation is performed using actual PMU synchrophasor measurements provided by a utility company. The model development and validation process ensures the accuracy of the developed model and makes for a realistic …

High Temperature Silicon Carbide Mixed-Signal Circuits For Integrated Control And Data Acquisition, Ashfaqur Rahman

Graduate Theses and Dissertations

Wide bandgap semiconductor materials such as gallium nitride (GaN) and silicon carbide have grown in popularity as a substrate for power devices for high temperature and high voltage applications over the last two decades. Recent research has been focused on the design of integrated circuits for protection and control in these wide bandgap materials. The ICs developed in SiC and GaN can not only complement the power devices in high voltage and high frequency applications, but can also be used for standalone high temperature control and data acquisition circuitry.

This dissertation work aims to explore the possibilities in high temperature …

8 Bit Split Array Based Charge Scaling Digital To Analog Converter With Rail To Rail Buffered Output, Sai Kiran Akula

Graduate Theses and Dissertations

This thesis presents the design, simulation and layout of a silicon carbide (SiC) 8 bit split array charge scaling digital to analog convertor (DAC). The converter consists of the charge scaling capacitor chain with two operational trans-conductance amplifiers (op amp) in voltage follower configuration. The op amps used in the design have the input common mode ranges of 0 to 11.2 V and 4.7V to 14.5V respectively. Additional logic circuit topologies are designed, which help to switch the op amps when needed to provide a rail to rail unity gain at the output. As the design is based on the …

Wireless Monitoring Of Driver's Pulse Rate And Temperature Using Hand Gloves Approach, Rohith Reddy Narala

Graduate Theses and Dissertations

There is growing concern about dangers correlated with driving, for people with known cardiovascular diseases. However, the association between having a chronic cardiovascular disease and being involved in a motor vehicle crash remains controversial. This study aims to monitor people with known medical emergencies or other medical conditions while driving [1]. It also helps the co-passengers to be cautious while the person is driving with an abnormal health condition. Designed it to be convenient and also can be easily adaptable by the end user.

The proposed project focuses on a wearable sensor glove that equipped with a pulse rate sensor, …

High-Frequency Transformer Design For Solid-State Transformers In Electric Power Distribution Systems, Roderick Javier Garcia Montoya

Graduate Theses and Dissertations

The objective of this thesis is to present a high- or medium-frequency transformer design methodology for Solid-State Transformer (SST) applications. SSTs have been proposed as a replacement of the traditional 50/60 Hz transformer in applications demanding high-power density. Moreover, due to the high penetration of distributed generation, DC grids, energy storage systems, and sensitive loads, SSTs have been considered as an enabling technology for envisioned future energy systems. These applications demand additional functionalities that may not be achieved with traditional transformers. For example, active power flow control, harmonic suppression, voltage regulation, voltage sag compensation, and reduced size and volume.

In …

Swelling-Etching Characterization Of Copper (I) Oxide - Pdms For The Development Of Micro/Nano - Particles Composite Mems Corrosion Sensor, Abdoul Kader Maiga

Graduate Theses and Dissertations

The primary objective for this thesis is to contribute to the understanding of the oxide removal process for a corrosion sensing device. The goal for designing such a device is for monitoring corrosion on metallic structures. The sensing material (6.35mm x 1mm discs) of the device is composed of copper (I) oxide particles mixed in some polydimethylsiloxane (PDMS). The PDMS, “housing,” is meant for controlling the oxidation rate through the sensing material. A solvent was used to facilitate the etchant diffusion through the PDMS matrix. Toluene and acetic acid were the ideal solvent and etchant, respectively, for carrying out the …

Broadband High Efficiency Fractal-Like And Diverse Geometry Silicon Nanowire Arrays For Photovoltaic Applications, Omar Hassan Al-Zoubi

Graduate Theses and Dissertations

Solar energy has many advantages over conventional sources of energy. It is abundant, clean and sustainable. One way to convert solar energy directly into electrical energy is by using the photovoltaic solar cells (PVSC). Despite PVSC are becoming economically competitive, they still have high cost and low light to electricity conversion efficiency. Therefore, increasing the efficiency and reducing the cost are key elements for producing economically more competitive PVSC that would have significant impact on energy market and saving environment. A significant percentage of the PVSC cost is due to the materials cost. For that, thin films PVSC have been …

The Effects Of Strain And Vacancies On The Electric And Vibrational Properties Of Ferroelectric Batio3 From First-Principles, Aldo Serge Michael Raeliarijaona

Graduate Theses and Dissertations

The studies of ferroelectricity (FE) are of technological significance because of the multitude of applicable properties that ferroelectric materials exhibit. The mastery, and control of these properties necessitate the knowledge of the fundamental physics governing these insulating materials.

In this dissertation I present the results of first-principles investigations of the behavior of the fundamental ferroelectric properties under strain, and in the presence of vacancies. In the first part I introduce the important FE properties, their common behavior, and their numerous valuable applications. Following this background on FEs, a review of theoretical methods is presented with topics such as: Density Functional …

Reducing Multiple Access Interference In Broadband Multi-User Wireless Networks, Ali Nayef Alqatawneh

Graduate Theses and Dissertations

This dissertation is devoted to developing multiple access interference (MAI) reduction techniques for multi-carrier multi-user wireless communication networks.

In multi-carrier code division multiple access (MC-CDMA) systems, a full multipath diversity can be achieved by transmitting one symbol over multiple orthogonal subcarriers by means of spreading codes. However, in frequency selective fading channels, orthogonality among users can be destroyed leading to MAI. MAI represents the main obstacle to support large number of users in multi-user wireless systems. Consequently, MAI reduction becomes a main challenge when designing multi-carrier multi-user wireless networks. In this dissertation, first, we study MC-CDMA systems with different existing …

Numerical Simulation Of Terahertz Wave Interaction With Breast Cancer Tumor Tissue Sections, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

This thesis presents numerical simulation of terahertz (THz) wave interaction with breast cancer tumor tissue sections. The obtained results are expressed in THz images of heterogeneous material that mimics the excised breast cancer tissue sections. The finite-element software package ANSYS High Frequency Structural Simulator (HFSS) was used in this work. HFSS is a full wave frequency domain three-dimensional (3D) electromagnetic simulation package. In this work, four breast cancer tissue models based on pathology images were simulated and images of the models were obtained at 1 THz. An incident Gaussian beam was raster scanned over tissue model configurations and the reflected …

Fabrication Of Sub-10 Nm Metallic Structures Via Nanomasking Technique For Plasmonic Enhancement Applications, Stephen Joseph Bauman

Graduate Theses and Dissertations

One area of nanoscience that has become popular in recent years is the study of optics at the nanoscale. Due to enhanced fabrication techniques, new geometries and improved dimensional resolutions have been allowing the creation of nanostructures for use in this area. Nanoscale geometries cause unique optical effects such as enhancement of the signal’s electric field strength at the surface of a substrate. Specifically, structures separated by nanogaps (10 nm and smaller) have been shown to exhibit strong field enhancement within the gaps. This has opened up the potential for surface enhanced spectroscopies, enhanced absorption for photovoltaics, and improved sensing …

Design, Fabrication, And Measurement Of A Multiple-Input Multiple-Output (Mimo) Antenna For Mobile Communication, Christopher Charles Arnold

Graduate Theses and Dissertations

This thesis presents the design, fabrication and characterization of a multiband uniplanar MIMO antenna for hand-held mobile communication devices on LTE, WLAN, and WMAN networks. The antenna design methodology combined a variety of broadbanding techniques that resulted in a single-layer hybrid monopole antenna coupled to a meander line element and parasitic structures. The 115×55×1.54 mm antenna was fabricated using an FR4 composite material and occupies only a fractional volume within the size of an average cellular phone allowing ample space to integrate with existing hardware. Characterization of the MIMO antenna included input impedance, scattering parameters and radiation pattern cross sections …

Text-Independent Speaker Identification Using Statistical Learning, Alli Ayoola Ojutiku

Graduate Theses and Dissertations

The proliferation of voice-activated devices and systems and over-the-phone bank transactions has made our daily affairs much easier in recent times. The ease that these systems offer also call for a need for them to be fail-safe against impersonators. Due to the sensitive information that might be shred on these systems, it is imperative that security be an utmost concern during the development stages. Vital systems like these should incorporate a functionality of discriminating between the actual speaker and impersonators. That functionality is the focus of this thesis.

Several methods have been proposed to be used to achieve this system …

Design Of Integrated Current Reference Circuits For A 180-Nanometer Bicmos Silicon Process, Timothy Max Megee

Electrical Engineering Undergraduate Honors Theses

The goal of this thesis is to provide design analysis, simulation results, and physical layout structure for three current references that are to be physically fabricated in a 180- nanometer BICMOS silicon process. The report briefly discusses the need for voltage and current references in analog circuit applications, before zooming in to examine three topologies being tailored to the needs of an integrated solar micro-inverter system. These topologies are: proportional to absolute temperature (PTAT), complementary to absolute temperature (CTAT), and constant across temperature (Constant) bias circuits. First, each topology is designed schematically to meet the needs of the micro-inverter system. …

Magnetic Amplifiers For Voltage Regulation Applications, Casey Morgan O'Grady

Electrical Engineering Undergraduate Honors Theses

The purpose of this thesis is to present research on magnetic amplifiers and to discuss how magnetic amplifiers are useful in voltage regulation applications. Beginning with a background in magnetics and magnetic properties, this thesis outlines the importance of the B-H curve and explains how to simulate the B-H curve of a saturable inductor using LtSpice. Furthermore, two saturable inductors can be aligned in antiparallel to create a magnetic amplifier. The theory of magnetic amplifiers is dated, but its simplistic design has benefits for modern applications. The magnetic amplifier acts as a variable impedance switch where a small amount of …

Mobile Health Sensing With Smart Phones, Abby Logan Wise

Electrical Engineering Undergraduate Honors Theses

Depression is a serious mental condition affecting many Americans and people across the world. Postpartum depression is a form of depression affecting women who have recently gone through childbirth. Postpartum depression can have serious symptoms that may affect not only the mother, but her newborn as well. Early detection of these symptoms is of critical importance to the welfare of the mother and her child. Many medical professionals express the need for postpartum screening being that treatment has proven to be very effective. This project aims to make early symptom detection convenient and reliable for mothers with newborns. This will …

Implementation Of Natural Switching Surface Control For A Flyback Converter, Ethan Storm Williams

Electrical Engineering Undergraduate Honors Theses

The flyback converter is an extremely common topology used for DC/DC power conversion. Widely used methods to control the flyback converter include voltage mode and current mode controllers. More recently, sliding mode control has been developed for the flyback converter. While these control methods may be considered adequate, the Natural Switching Surface (NSS) sliding mode control method detailed in this thesis presents a more robust controller. NSS control eliminates the effects presented from variations in components and design as well as minimizes the effects from external disturbances. This thesis steps through the complete design and implementation process of a NSS …

Fusion Of Short-Mid Wavelength Infrared Image And Long Wavelength Image Using Discrete Wavelet Transform For Image Quality Enhancement, Rocky Hedrick

Electrical Engineering Undergraduate Honors Theses

Infrared technology advancements have led to an expansive set of infrared applications in both the private and public sectors. New materials and manufacturing techniques have continued to reduce the cost while improving the quality of infrared cameras, but the cost is still high when compared to the cost versus quality of visible light spectrum cameras. Innovative image processing techniques can be implemented to help bridge this gap between the cost and quality of infrared cameras. The goal of this research is to improve the overall quality of infrared imaging by fusing short-mid wavelength infrared images and long wavelength images of …

Top-Down Aluminum Induced Crystallization For Photovoltaics, Seth Daniel Shumate

Graduate Theses and Dissertations

Passivating silicon solar cell surfaces is critical to fabricating very high efficiency and low cost photovoltaic devices. The sun-facing surface of the solar cell, known as the emitter, is particularly important when designing a solar cell. This work focused first on an alternative method of forming the emitter of silicon solar cells, and secondly on a method for improving the surface passivation of both these non-traditional and standard n-type solar cells.

Top-down aluminum induced crystallization (TAIC) was used for forming a polycrystalline silicon layer from amorphous silicon using aluminum to catalyze the crystallization at much lower temperatures than otherwise possible. …

Enhancement Of The Performance Of Gaas Based Solar Cells By Using Plasmonic, Anti-Reflection Coating And Hydrophobic Effects, Yahia Fayiz Makableh

Graduate Theses and Dissertations

Investigation of renewable energy resources is gaining huge momentum in recent years due to the limited fossil fuels, and their detriment impact on the environment. Solar energy is promising to meet the increased energy demand. In order to achieve this goal, solar energy has to be harvested efficiently at low cost. Therefore, higher efficiency solar cells are the primary focus of research worldwide. Photovoltaics based on InAs/GaAs intermediate band solar cells and their device performance enhancements are investigated in this dissertation. The device enhancement is carried out by surface modification methods. The dissertation work is inspired by the need of …

Environmental Reliability Of Thin Film Sealing On Thick Film Ltcc, Charles R. Bourland

Graduate Theses and Dissertations

As electronic components and systems become more intricate and expand into new realms of use case scenarios, new materials systems must be explored. With new systems comes the balancing acts of cost and reliability. Presented here is a thesis that explores a new hybrid-electronics packaging system using low temperature co-fired ceramics, referred to as LTCC. An LTCC system was designed to explore the environmental reliability of numerous thick film LTCC features and parameters. A key element was to explore how a thin film metallization stack up used to cap or seal underlying thick film structures would decrease environmental susceptibility while …

Single-Walled Carbon Nanotube Arrays For High Frequency Applications, Asmaa Elkadi

Graduate Theses and Dissertations

This dissertation presents a thorough analysis of semiconducting Single-Walled Carbon Nanotube-based devices, followed by a test structure fabrication and measurements.

The analysis starts by developing an individual nanotube model, which is then generalized for many nanotubes and adding the parasitic elements. The parasitic elements appear when forming the device electrodes degrade the overall performance.

The continuum model of an individual nanotube is developed. A unique potential function is presented to effectively describe the electron distribution in the carbon nanotube subsequently facilitating solving Schrödinger's equation to obtain the energy levels, and to generalize the model for many nanotubes.

It is shown …

High Temperature Cmos Silicon Carbide Asynchronous Circuit Design, Landon John Caley

Graduate Theses and Dissertations

Designing a digital circuit to operate in an extreme temperature range is a challenge with increasing demand for a solution. Large variations in temperature have a distinct impact on electron mobilities causing substantial changes to the threshold voltage of the devices. These physical changes affect the setup and hold times of clocked components, such as D-Flip Flops, of a traditional synchronous digital circuit. Focusing primarily on high temperature circuit operation, this dissertation presents a digital circuit design methodology pairing an asynchronous circuit design paradigm called NULL Convention Logic (NCL) as well as traditional Boolean circuitry with a wide-bandgap semiconductor material, …