Engineering Commons^™

Characterization And Quality Assessment Of Smart Polymer Systems Fabricated By Using 3d Printing Technique, Carlos Alejandro Garcia Rosales

Open Access Theses & Dissertations

Shape memory polymers (SMPs) are classified as smart materials due to their inherent stimulus-induced response. SMP is capable of recovering its original shape from a high degree of deformation by applying an external stimulus such as thermal energy. Other stimuli are electricity, light, chemical, and magnetic field. Shape memory polymers (SMPs) and its fabrication process has recently attracted much attention as a result of their potential application as soft active materials. Demonstration of SMP systems fabricated via 3D printing technologies has been one of the most popular attempts. This Dissertation presents an integration of two commercial SMP materials (DiAPLEX and …

Energy Management And Control Of Smart Power Distribution Systems, Eric Galvan

Open Access Theses & Dissertations

With the development of distributed energy resources (DERs) and advancements in technology, microgrids (MGs) appear primed to become an even more integral part of the future distribution grid. In this transition to the smart power grid of the future, MGs must be properly managed and controlled to allow efficient integration of DERs. Over the past years, there has been rapid adoption of roof-top solar photovoltaic (PV) and battery electric vehicles (BEVs). Although roof-top solar PV and BEVs can provide environmental benefits (e.g., reduction of emissions), they also create various challenges for power system operators. For example, roof-top solar PV generation …

Artificial Intelligence In The Assessment Of Transmission And Distribution Systems Under Natural Disasters Using Machine Learning And Deep Learning Techniques In A Knowledge Discovery Framework, Rossana Villegas

Open Access Theses & Dissertations

Warming trends and increasing temperatures have been observed and reported by federal agencies, such as the National Oceanic and Atmospheric Administration (NOAA). Extreme-weather events, especially hurricanes, tornadoes and winter storms, are among the highly devastating natural disasters responsible for massive and prolonged power outages in Electrical Transmission and Distribution Systems (ETDS). Moreover, the failure rate probability of any system component under extreme-weather tends to increase in the impacted geographic area. This Dissertation proposes an Artificial Intelligence (AI) Decision Support System that can predict damage in the ETDS and allow operators to mitigate disastrous extreme weather events. The document reports the …

Material Characterizations Of Organic-Inorganic Halide Perovskites Using Various Deposition Techniques For Planar Perovskite Solar Cell, Shaimum Shahriar

Open Access Theses & Dissertations

Organic-inorganic halide perovskites have rapidly become emerging materials for photovoltaic applications. Strong characterization methods are needed to fully comprehend the chemistry and composition of perovskite solar cells. Understanding the interaction between layers inside a cell and how they react with the environment is important to achieve optimum manufacturing processes, and improve the efficiency of perovskite solar cells. The present work demonstrates the material characterizations of organic-inorganic halide perovskites using (i) one-step deposition, (ii) two-steps deposition, (iii) solvent-to-solvent extraction, and (iv) mixed-cation solution processing. Investigations by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) have been undertaken …

Microstructure Evolution Of Chalcogenide Materials Via Molecular Dynamics, Sharmin Abdullah

Open Access Theses & Dissertations

The properties of a material are defined by its granular microstructure which is determined by its grain evolution and the types of grain boundaries present in the structure. For example, the performance of Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) solar cells can be affected by the presence of grain boundaries which makes the study of grain structure evolution a very important part of solar cell performance optimization. Grain boundary mobilities are important properties in material science and engineering as they determine grain structures under given processing and operating conditions.

In this thesis, several computational tools were used to analyze the formation and …

Conductivity Modulation In Strained 2d Transition- Metal- Dichalcogenides Via Micro- Electro- Mechanical Actuation, Aldo Ivan Vidaña

Open Access Theses & Dissertations

In this thesis, strain-induced conductivity modulation in bi-layer molybdenum disulfide (MoS2) flakes is experimentally investigated and modeled. Uniaxial tensile strain in the MoS2 flakes is achieved using a micro-electro-mechanical (MEM) actuator. Conductivity ratios up to 400 are demonstrated. Theoretical predictions of conductivity versus applied voltage in the MEMS-MoS2 device match experimental data reasonably well using only the effective width of the TMDC flakes as the sole fitting parameter. The amount of strain induced in the MoS2 flakes was determined to be as high as 2.7% for one flake using the model fitted to the experiment data. The switching energy required …

Hfo Detector Based On Eeg Mean Energy Change Detection, Raul Ontiveros

Open Access Theses & Dissertations

The main goal of this work is to support automated seizure prediction by identifying preictal states using multiple detectors of high-frequency oscillations (HFOs). Assessment of HFOs from a seizure onset zone may be facilitated using automatic HFO detectors. However, studies have shown that HFOs can be generated by physiological or pathological brain processes. Distinguishing between pathological and physiological HFOs is challenging due to a lack of discriminant information in signals' morphology and other characteristics. Other complicating factors include a lack of consistency in definitions of HFO frequency ranges, the need for expert verification of HFO detection, and lack of robustness …