Engineering Commons^™

High Frequency Ltcc Based Planar Transformer, Adithya Venkatanarayanan

Graduate Theses and Dissertations

As we move towards high power and higher frequency related technology, conventional wire-wound magnetics have their own limitations which has led path to the development of planar based magnetic materials. Nowadays more planar magnetic technology has been employed because it is easier to fabricate them. The planar magnetic is a transformer or an inductor that replaces the wire-wound transformer or inductors which generally uses copper wires. One of the main reasons why we move to planar magnetic technology is its operation at higher frequency which provides higher power density. This study explains in detail about the design and fabrication of …

Adaptive Boundary Control Using The Natural Switching Surfaces For Flyback Converters, Luciano Andres Garcia Rodriguez

Graduate Theses and Dissertations

The derivation and implementation of the natural switching surfaces (NSS) considering certain parametric uncertainties for a flyback converter operating in the boundary conduction mode (BCM) is the main focus of this paper. The NSS with nominal parameters presents many benefits for the control of nonlinear systems; for example, fast transient response under load-changing conditions. However, the performance worsens considerably when the converter actual parameters are different from the ones used in the design process. Therefore, a novel control strategy for NSS considering the effects of parameter uncertainties is proposed. This control law can estimate and adapt the control trajectories in …

Design And Optimization Of A High Power Density Silicon Carbide Traction Inverter, Tyler Adamson

Graduate Theses and Dissertations

This project was initiated with the goal of demonstrating a 3-phase silicon carbide based 150-kW 25 kW/L DC-AC power conversion unit capable of operation with coolant temperatures up to 90°C. The project goals were met and exceeded by first analyzing the established inverter topologies to find which one would yield the highest power density while still meeting electrical performance needs in the 150-kW range. Following topology selection, the smallest silicon carbide power module that met the electrical requirements of the system was found through experimental testing and simulation. After a power module selection was finalized, a DC link capacitor bank …

Development Of A Comsol Microdialysis Model, Towards Creation Of Microdialysis On A Chip With Improved Geometries And Recovery, Patrick Pysz

Graduate Theses and Dissertations

Microdialysis (µD) sampling is a diffusion-limited sampling method that has been widely used in different biomedical fields for greater than 35 years. Device calibration for in vivo studies is difficult for current non-steady state analytes of interest correlated with both inflammatory response and microbial signaling molecules (QS); which exist in low ng/mL to pg/mL with molecular weights over a wide range of 170 Da to 70 kDa. The primary performance metric, relative recovery (RR), relating the collected sample to the extracellular space concentration varies from 10% to 60% per analyte even under controlled bench-top conditions. Innovations in microdialysis device design …

Interfacial Contact With Noble Metal - Noble Metal And Noble Metal - 2d Semiconductor Nanostructures Enhance Optical Activity, Ricardo Raphael Lopez Romo

Graduate Theses and Dissertations

Noble metal nanoparticles and two-dimensional (2D) transition metal dichalcogenide (TMD) crystals offer unique optical and electronic properties that include strong exciton binding, spin-orbital coupling, and localized surface plasmon resonance. Controlling these properties at high spatiotemporal resolution can support emerging optoelectronic coupling and enhanced optical features. Excitation dynamics of these optical properties on physicochemically bonded mono- and few-layer TMD crystals with metal nanocrystals and two overlapping spherical metal nanocrystals were examined by concurrently (i) DDA simulations and (ii) far-field optical transmission UV-vis spectroscopic measurements. Initially, a novel and scalable method to unsettle van der Waals bonds in bulk TMDs to prepare …

Exploring Convergence Of Snake Skin-Inspired Texture Designs And Additive Manufacturing For Mechanical Traction, Catherine Sue Tiner

Graduate Theses and Dissertations

This research focuses on the understanding, development, and additive manufacture of a 3D printed snake skin-inspired texture pattern. The design functionalities of snake skin were determined through the study of the snake species Python Regius otherwise known as the ball python. Each scale of a snake has hierarchical texture with hexagonal macro-patterns aligned on the ventral surface of the skin with overriding anisotropic micro textured patterns such as denticulations and fibrils. Using a laser-powder bed fusion (L-PBF) process, 420 stainless steel samples were 3D printed which closely resemble the above described directional texture of natural snake skin. This printed surface …

Evaluation And Analysis Of Null Convention Logic Circuits, John Davis Brady

Graduate Theses and Dissertations

Integrated circuit (IC) designers face many challenges in utilizing state-of-the-art technology nodes, such as the increased effects of process variation on timing analysis and heterogeneous multi-die architectures that span across multiple technologies while simultaneously increasing performance and decreasing power consumption. These challenges provide opportunity for utilization of asynchronous design paradigms due to their inherent flexibility and robustness.

While NULL Convention Logic (NCL) has been implemented in a variety of applications, current literature does not fully encompass the intricacies of NCL power performance across a variety of applications, technology nodes, circuit scale, and voltage scaling, thereby preventing further adoption and utilization …

Fractional Order State Feedback Control For Improved Lateral Stability Of Semi-Autonomous Commercial Heavy Vehicles, Rasheed Mazen Abdulkader

Graduate Theses and Dissertations

With the growing development of autonomous and semi-autonomous large commercial heavy vehicles, the lateral stability control of articulated vehicles have caught the attention of researchers recently. Active vehicle front steering (AFS) can enhance the handling performance and stability of articulated vehicles for an emergency highway maneuver scenario. However, with large vehicles such tractor-trailers, the system becomes more complex to control and there is an increased occurrence of instabilities. This research investigates a new control scheme based on fractional calculus as a technique that ensures lateral stability of articulated large heavy vehicles during evasive highway maneuvering scenarios. The control method is …

Synthesis Of Cellulose Nanocrystal-Gold Nanoparticle Hybrid System For Surface Plasmon-Enhanced Property, Mahshid Iraniparast

Graduate Theses and Dissertations

Gold nanoparticles (AuNPs) have been brought to the forefront of various applications, ranging from theranostics, to organic photovoltaics, to biosensing owing to their localized surface plasmon resonance (LSPR) property. However, this property needs to be improved in order to allow for high sensitivity and quantitative detection of biomolecules. Hybrids of AuNPs with low-dielectric cellulose nanocrystal (CNCs) would yield enhancement of the LSPR property, which is driven by the confinement of electron oscillation at their interfaces. This study proposed a seed-mediated growth method to synthesize hybrids of CNCs-AuNPs. Sulfate groups on the surface of CNCs served as the sites for the …

Toolpath Planning Methodology For Multi-Gantry Fused Filament Fabrication 3d Printing, Hieu Trung Bui

Graduate Theses and Dissertations

Additive manufacturing (AM) has revolutionized the way industries manufacture and prototype products. Fused filament fabrication (FFF) is one of the most popular processes in AM as it is inexpensive, requires low maintenance, and has high material utilization. However, the biggest drawback that prevents FFF printing from being widely implemented in large-scale production is the cycle time. The most practical approach is to allow multiple collaborating printheads to work simultaneously on different parts of the same object. However, little research has been introduced to support the aforementioned approach. Hence a new toolpath planning methodology is proposed in this paper. The objectives …

Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi

Graduate Theses and Dissertations

This thesis presents and evaluates a solution for unbalanced current loading in three-phase distribution systems. The proposed solution uses the flying capacitor multilevel converter as its main topology for an application known as Unbalanced Current Static Compensator. The fundamental theory, controller design and prototype construction will be presented along with the experimental results. The Unbalanced Current Static Compensator main objective is the balancing of the up-stream currents from the installation point to eliminate the negative- and zero-sequence currents originated by unbalanced single-phase loads.

Three separate single-phase flying capacitor converters are controlled independently using a d-q rotating reference frame algorithm to …

Switching Trajectory Control For High Voltage Silicon Carbide Power Devices With Novel Active Gate Drivers, Shuang Zhao

Graduate Theses and Dissertations

The penetration of silicon carbide (SiC) semiconductor devices is increasing in the power industry due to their lower parasitics, higher blocking voltage, and higher thermal conductivity over their silicon (Si) counterparts. Applications of high voltage SiC power devices, generally 10 kV or higher, can significantly reduce the amount of the cascaded levels of converters in the distributed system, simplify the system by reducing the number of the semiconductor devices, and increase the system reliability.

However, the gate drivers for high voltage SiC devices are not available on the market. Also, the characteristics of the third generation 10 kV SiC MOSFETs …

Growth Of Indium Nitride Quantum Dots By Molecular Beam Epitaxy, Steven P. Minor

Graduate Theses and Dissertations

Over the last decade, the evolution of the global consciousness in response to decreasing environmental conditions from global warming and pollution has led to an outcry for finding new alternative/clean methods for harvesting energy and determining ways to minimize energy consumption. III-nitride materials are of interest for optoelectronic and electronic device applications such as high efficiency solar cells, solid state lighting (LEDs), and blue laser (Blu-ray Technology) applications. The wide range of direct band gaps covered by its alloys (0.7eV-6.2eV) best illustrates the versatility of III-nitride materials. This wide range has enabled applications extending from the ultraviolet to the near …

Polarization Properties Of Airy And Ince-Gaussian Laser Beams, Sean Michael Nomoto

Graduate Theses and Dissertations

The description of polarization states of laser light as linear, circular polarization within the paraxial scalar wave approximation is adequate for most applications. However, this description falls short when considering laser light as an electromagnetic wave satisfying Maxwell's equations. An electric field with a constant unit vector for direction of the field and a space dependent complex scalar amplitude in the paraxial wave approximation does not satisfy Maxwell equations which, in general, requires all three Cartesian components of electric and magnetic fields associated for a nonzero laser beam to be nonzero.

Physical observation of passing a linearly polarized laser through …

Backstepping Control And Transformation Of Multi-Input Multi-Output Affine Nonlinear Systems Into A Strict Feedback Form, Khalid Salim D. Alharbi

Graduate Theses and Dissertations

This dissertation presents an improved method for controlling multi-input multi-output affine nonlinear systems. A method based on Lie derivatives of the system's outputs is proposed to transform the system into an equivalent strict feedback form. This enables using backstepping control approaches based on Lyapunov stability and integrator backstepping theory to be applied. The geometrical coordinate transformation of multi-input multi-output affine nonlinear systems into strict feedback form has not been detailed in previous publications. In this research, a new approach is presented that extends the transformation process of single-input single-output nonlinear. A general algorithm of the transformation process is formulated. The …

Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak

Graduate Theses and Dissertations

With the introduction of sophisticated electronic gadgets which cannot sustain interruption in the provision of electricity, the need to supply uninterrupted and reliable power supply, to the consumers, has become a crucial factor in the present-day world. Therefore, it is customary to correctly identify fault locations in an electrical power network, in order to rectify faults and restore power supply in the minimum possible time. Many automated fault location detection algorithms have been proposed, however, prior art requires topological and physical information of the electrical power network. This thesis presents a new method of detecting fault locations, in transmission as …

H2 Control For Improved Stability Of Multi-Area Electric Power System With High Levels Of Inverter-Based Generation, Muthanna Abdulkareem Al-Sarray

Graduate Theses and Dissertations

Increased generation capacity from non-dispatchable energy resources such as wind and solar has created challenges to ensuring the reliable delivery of electric power. This research develops a systematic three-step method of assessing the reliability of electric power systems under a variety of different possible fault conditions to ensure that overall system stability is preserved in a manner the meets regulatory requirements. The first step is a risk-based reliability method (RBRM) that accounts for the probability of a line outage versus the severity of impact. This allows system planners to judiciously allocate expenses for reliability improvements based on the greatest economic …

Characterization Of Hydride Vapor Phase Epitaxy Grown Gan Substrates For Future Iii-Nitride Growth, Alaa Ahmad Kawagy

Graduate Theses and Dissertations

The aim of this research is to investigate and characterize the quality of commercially obtained gallium nitride (GaN) on sapphire substrates that have been grown using hydride vapor phase epitaxy (HVPE). GaN substrates are the best choice for optoelectronic applications because of their physical and electrical properties. Even though HVPE GaN substrates are available at low-cost and create the opportunities for growth and production, these substrates suffer from large macro-scale defects on the surface of the substrate.

In this research, four GaN on sapphire substrates were investigated in order to characterize the surface defects and, subsequently, understand their influence on …

Investigation Of Critical Technologies Of Chemical Vapor Deposition For Advanced (Si)Gesn Materials, Joshua Matthew Grant

Graduate Theses and Dissertations

The development of new materials for efficient optoelectronic devices from Group IV elements is the heart of Group IV photonics. This has direct ties to modern technology as the foundation for the electronics industry is silicon. This has driven the development of silicon-based optoelectronics using these other Group IV materials as silicon is a poor optical material due to its indirect band gap when compared to the III-V semiconductors that are used by most of the optoelectronics industry. While efforts have been made to integrate III-V materials onto silicon substrates, the incompatibility with the complementary metal oxide semiconductor process has …

Hardware Ip Classification Through Weighted Characteristics, Brendan Mcgeehan

Graduate Theses and Dissertations

Today’s business model for hardware designs frequently incorporates third-party Intellectual Property (IP) due to the many benefits it can bring to a company. For instance, outsourcing certain components of an overall design can reduce time-to-market by allowing each party to specialize and perfect a specific part of the overall design. However, allowing third-party involvement also increases the possibility of malicious attacks, such as hardware Trojan insertion. Trojan insertion is a particularly dangerous security threat because testing the functionality of an IP can often leave the Trojan undetected. Therefore, this thesis work provides an improvement on a Trojan detection method known …

A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, Aminta Naidili Castillo Robles

Graduate Theses and Dissertations

This thesis presents the design, simulation and test results of a silicon germanium (SiGe) complementary metal-oxide-semiconductor (CMOS) linear regulator. The objective of the circuit is to power other analog devices regardless of the load current and input voltage changes. The application of this regulator is to be part of a project developing a miniaturized semiconductor platform that can be inserted into stems of crops in order to measure data inside the plant and then send it wirelessly to the user. The linear regulator was designed on a BiCMOS SiGe 0.13µm which is a GlobalFoundries process. It has been tested at …

Experimental And Computational Study On Magnetic Nanowires Of Layered Titanates, Caleb Layne Heath

Graduate Theses and Dissertations

The intricate nanostructures of layered titanates are unique among nanomaterials due to their easy and inexpensive syntheses. These nanomaterials have been proven valuable for use in industries as varied as energy, water treatment, and healthcare, and can be produced at industrial scales using already existent equipment. They have complex morphology, and surface structure well suited to chemical modification and doping. However, there is a longstanding debate on their lattice structure after the doping. There is a long-unmet need to understand, using both experimental and simulation methods, how dopants alter the clay-like layered crystal structure and associated physical and chemical properties. …

Plasmonic Properties Of Nanoparticle And Two Dimensional Material Integrated Structure, Desalegn Tadesse Debu

Graduate Theses and Dissertations

Recently, various groups have demonstrated nano-scale engineering of nanostructures for optical to infrared wavelength plasmonic applications. Most fabrication technique processes, especially those using noble metals, requires an adhesion layer. Previously proposed theoretical work to support experimental measurement often neglect the effect of the adhesion layers. The first finding of this work focuses on the impact of the adhesion layer on nanoparticle plasmonic properties. Gold nanodisks with a titanium adhesion layer are investigated by calculating the scattering, absorption, and extinction cross-section with numerical simulations using a finite difference time domain (FDTD) method. I demonstrate that a gold nanodisk with an adhesive …

Local And Central Controllers For Microgrids, Edgar Ariel Escala Calame

Graduate Theses and Dissertations

The main objective of this thesis is to serve as a guide, so readers are able to learn about microgrids and to design simple controllers for different AC microgrid applications. In addition, this thesis has the objective to provide examples of simulation cases for the hierarchical structure of a basic AC microgrid which can be used as a foundation to build upon, and achieve more complex microgrid structures as well as more sophisticated power-converter control techniques.

To achieve these objectives, the modeling of voltage source converters and control design in the z-domain are presented. Moreover, the implementation and transient analysis …

Asynchronous Circuit Synthesis Using Multi-Threshold Null Convention Logic, Nicholas Renoudet Mize

Graduate Theses and Dissertations

As the demand for an energy-efficient alternative to traditional synchronous circuit design grows, hardware designers must reconsider the traditional clock tree. By doing away with the constrains of a clock, asynchronous sequential circuit designs can achieve a much greater level of efficiency. The utilization of asynchronous logic synthesis flows has enabled researchers to better implement asynchronous circuit designs which have been optimized using the same industry standard tools that are already used in sequential synchronous designs. This thesis offers a new flow for such tools which implements the MTNCL asynchronous circuit architecture.

Model Development And Assessment Of The Gate Network In A High-Performance Sic Power Module, William Austin Curbow

Graduate Theses and Dissertations

The main objective of this effort is to determine points of weakness in the gate network of a high-performance SiC power module and to offer remedies to these issues to increase the overall performance, robustness, and reliability of the technology. In order to accomplish this goal, a highly accurate model of the gate network is developed through three methods of parameter extraction: calculation, simulation, and measurement. A SPICE model of the gate network is developed to analyze four electrical issues in a high-speed, SiC-based power module including the necessary internal gate resistance for damping under-voltage and over-voltage transients, the disparity …