Additive manufacturing has become a promising method for the fabrication of inexpensive, green, flexible sensors and electronics. Printed electronics on low- temperature substrates are very appealing for the flexible hybrid electronics market for their use in disposable and biocompatible electronic applications and in areas like packaging, wearables, and consumer electronics....
As the fifth generation of mobile communication systems (5G) is being deployed, massive multiple-input multiple-output (MIMO) serves as one of its enabling technologies where reliable and ultra low latency communications are achieved while being power and spectrum efficient. This thesis studies the security aspect of massive MIMO system from the...
Ring Amplifier serves as a great candidate both for precision amplification and fast integration in the discrete time system. It can be utilized in high-performance analog-to-digital converters (ADCs). In high-speed ADC utilizing pipelined architectures with residue amplification, Successive-Approximation Register (SAR) ADCs as the sub-ADC and power efficient Ring Amplifier based...
Nucleation in atomic layer deposition (ALD) determines how many cycles are required to initiate growth and to form a continuous film. Nucleation has been exploited for the formation of nanoparticles, catalysts, and for area-selective ALD. Although sometimes overlooked or misrepresented in ALD reports, nucleation is also critical for multicomponent ALD...
Nowadays, wireless communication systems use high-order quadrature amplitude modulation (QAM) together with orthogonal frequency-division multiplexing (OFDM) to increase the link capacity and robustness. These signals always have large peak-to-average power ratio (PAPR) and require power amplifiers (PAs) achieve both high efficiency and linearity simultaneously. For the efficiency, the complementary metal...
Enabling accurate and automated identification of wireless devices is critical for ensuring secure and authenticated data communication in large-scale networks such as IoT networks. In the aim of devising practical identification techniques that are immune to spoofing, hardware-driven RF fingerprinting using deep neural networks, which leverages the inevitable presence of...
This research presents the design of three nonlinear model predictive controllers (NMPCs) for floating oscillating water column (OWC) wave energy converters (WECs) array to maximize generated power, augmented with the control of the high-speed stop valves (HSSVs). Key to this design is the development of a high-fidelity discretized model for...
This work gives some theory and efficient design of binary block codes capable of controlling the deletions of the symbol “0” (referred to as 0-deletions) and/or the insertions of the symbol “0” (referred to as 0-insertions). This problem of controlling 0-deletions and/or 0-insertions (referred to as symmetric 0-errors) is shown...
There are five main contributions of this dissertation. The first contribution is new closed-form expressions for channel capacity of a new class of channel matrices. The second contribution is the discovery of the structure for optimal binary quantizer and the associated methods for finding an optimal quantizer that maximizes mutual...
In this paper, a Direction of Arrival (DOA) based system is proposed. This method searches the direction relative to the array to find where the signal source is located. The proposed system can achieve sub-meter level accuracy with a near real-time update rate. Also, we introduced several refinement methods including...
With rising sea levels and more frequent exposure to extreme storms, coastlines worldwide are vulnerable to increased erosion and loss of natural marsh lands. In an effort to lessen these impacts, there is a growing practice of adapting hard or “gray” coastline protection techniques to more nature-based features that promote...
Emerging fifth generation (5G) and beyond 5G communication networks are stimulating the design of radio-frequency (RF) and millimeter-wave (mmWave) integrated circuits for wireless transceivers systems. While co-integration of active circuits and diverse passive components becomes feasible at these high operating frequencies, circuit design is faced with significant challenges due to...
An accurate state estimation plays an essential role in power system operation and planning in energy management systems. However, existing multi-area state estimation researches have not focused on the importance of system clustering. The clustering mechanism divides or partitions a system according to user-defined criteria. Few published research works have...
Engineering capstone projects are intended as a bridge from school to professional practice in which students work in teams to use learned knowledge and skills to complete real-world engineering projects. However, while the majority of time in many undergraduate programs is devoted to development of technical knowledge and skills, there...
How should reinforcement learning (RL) agents explain themselves to humans not trained in AI? To gain insights into this question, we conducted a 124 participant, four-treatment experiment to compare participants’ mental models of an RL agent in the context of a simple Real-Time Strategy (RTS) game. The four treatments isolated...
Harvesting energy from ambient sources can provide power autonomy to energy efficient electronics and sensors. The last decade has seen a multitude of ways to scavenge energy from various sources like solar, thermal, electromagnetic, electrostatic, piezo-electric and many more. Thermal energy from human body heat is ubiquitous and can be...
Over the last decades, CMOS-integrated sensors have made impressive progress in performance, form-factor, and energy-efficiency for various applications such as imaging, physical/chemical sensing, bio/health monitoring. In the era of the artificial intelligence (AI) and the internet-of-things (IoT), such CMOS-integrated sensors are essential for massive and comprehensive data acquisition, where sensing...
The testing of nuclear fuel under reactivity-initiated accident (RIA) conditions is paramount for the better understanding of the fuel’s behavior during this transient accident events. The Transient Reactor Test (TREAT) facility is a nuclear reactor that will be capable of recreating the thermal-hydraulic and neutronic boundary conditions representative of RIA...
Traditional bus-based interconnects are simple and easy to implement, but the scalability is greatly limited. While router-based networks-on-chip (NoCs) offer superior scalability, they also incur significant power and area overhead due to complex router structures. In this thesis, a new class of on-chip networks, referred to as Routerless (RL) NoCs,...
Wearable sensors with an inertial measurement unit (IMU) are popular for indoor positioning and activity pattern detection. The IMUs can be connected to a wireless transmission module, allowing users to monitor and process motion-related parameters remotely. Because of the complexity and uncertainty of signals in indoor environments, a radio frequency...
Traditional approaches to streaming H.264 video over a network typically rely on a single method of transport (i.e., reliable or unreliable) and/or use static values for parameters that can have a significant negative impact on the perceptual quality of the received video. This dissertation presents a dynamic method for wireless...
With the rapid growth of worldwide internet traffic in data centers and clouds, silicon photonics has been utilized to provide enormous data bandwidth and outstanding energy efficiency over electronics. Computing servers and storage servers that are connected by communication links are relying more on optical rather than electrical means mainly...
Structure-property relationships have always underpinned the field of solid state chemistry; dependable structural descriptions are integral to understanding and controlling the physical properties of inorganic compounds old and new. While a handful of crystal structures are celebrated for their versatility, flexibility, and functionality, the existence of more exotic structures is...
Real time indoor positioning awareness systems aim to add localization capabilities to upcoming wireless technologies that are quickly becoming an important feature for indoor environment. RF-based impulse-radio ultra-wideband (IR-UWB) is a promising technology for in-door positioning systems due to obstacle penetration capabilities, immunity to multi-path and fading, and high resolution....
Due to their viscoelastic properties, polymers and hydrogels are widely used in many applications. In this study, the viscoelastic properties of elastomer polymers were investigated for a series of hydrogel, hydrogel composites and silicon materials. A primary application for hydrogels and hydrogel composites is as a replacement for the degenerated...
Fe25Co25Ni25Cr25-XMoX High Entropy Alloys were fabricated in mini arc-melter and then cast into 4mm diameter cylinders by injection casting technique and 1cm diameter cylinders by water quenching technique. Heat transfer modeling during solidification of FeCoNiCr HEA was simulated. Combining X-Ray Diffraction, Optical Microscopy, Scanning Electron Microscope, Energy Dispersive X-ray analysis,...
This dissertation focuses on extending the application scope of surface enhanced infrared absorption spectroscopy to gas sensing. The method we propose is incorporating plasmonic nanostructures with nano-composite material, metalorganic framework, which can selectively preconcentrate certain gas molecules into the nanopores. The preconcentrating property is first demonstrated by applying metal-organic framework...
Earth’s mantle extends to nearly 3000 km depth, comprises >80 % of Earth’s total volume, and has the largest influence on the primordial and radiogenic heat budget. Despite its importance, the structure and composition of the mantle is still debated. There are three primary models for Earth’s mantle structure that...
High purity niobium metal is used in the construction of superconducting radio frequency (SRF) cavities in superconducting particle accelerators, such as the Large Hadron Collider (LHC) at CERN or the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The usual method for characterizing the impurities in this niobium, the...
Inkjet printing offers a cost effective, highly customizable method for rapid manufacturing of functional devices with minimal material waste. Although this method has been used for a variety of composites, little work has been done in the area of 3D printing magnetic composites. Presented here is a process for inkjet...
Threshold-based time of arrival (TOA) estimation is a technique for high-precision indoor localization. Existing threshold selection methods, such as xed thresh- old and normalized threshold methods, do not consider the signal-to-noise radio (SNR) value at the receiver. This is not desired for high-precision positioning. A proper threshold value depends on...
Optical wireless communication (OWC) is an alternative to radio frequency (RF)communication with a signi cantly larger and unregulated spectrum. In OWC systems, optical orthogonal frequency division multiplexing (O-OFDM) with intensity modulation and direct detection (IM/DD) is commonly used. There are two common signal structures in most OWC systems based on...
Bulk metallic glasses (BMGs) are relatively new amorphous materials that have received much attention in recent years. Rapid cooling methods from the liquid state provides the possibility to bypass crystallization during solidification. Due to the lack of crystal defects such as grain boundaries and dislocations, BMGs can have some special...
In the highly alkaline environment of concrete, carbon steel rebar is protected against corrosion by a passive oxide/oxyhydroxide film. Understanding the characteristics of this passive film, and how it depassivates, is the key for mitigating problems associated with steel corrosion in concrete. Although a large number of electrochemical and analytical...
Digital Image Correlation(DIC) is one of full-field strain measurement techniques devel- oped in recent decades, which has been well-demonstrated to conduct the mechanical properties study of solid materials, by collecting data using digital cameras. X-ray to- mography(CT) imaging helps the correlation techniques expanded to three dimensional investigation of materials, known...
Lead zirconate titanate (PZT) is the dominant ferroelectric material in the market due to its excellent piezoelectric properties, relatively high Curie transition temperature (T[subscript C]), low cost, etc. However, because of emerging applications with requirements for high temperature (T[subscript C] > 400 °C) ferroelectrics, researchers are increasingly looking at alternative...
In this dissertation, my research work on excited state dynamics of small organic molecules in solutions is presented. Using femtosecond stimulated Raman spectroscopy (FSRS) as the main experimental tool, the excited state hydrogen-bonding dynamics (ESHBD) of Coumarin 102, a common laser dye molecule, in ethanol solution is examined with <150...
The ability to engineer stiffness and strength in any desired direction make composites an ideal material candidate for various applications when compared to their traditional isotropic counterparts. In spite of this, the ability to model the material response in composites has yet to be fully explored. Composite research largely focuses...
Simulation models were developed to explore the reversible nature of gecko dry
adhesion system. The central idea of this model is that even with a small moment imparted on the contact tip, the seta can be easily ad-adhered. It is shown that this contact condition is very sensitive, but can...
Current cadmium telluride and copper indium gallium diselenide thin-film solar cells
(TFSCs) utilize thick absorbers (2 - 4 μm). For efficient carrier extraction in these TFSCs,
the absorber layer requires high carrier mobilities and a long minority carrier lifetime, which
necessitates the use of a high purity, defect-free thin film....
To improve the performance of solid oxide fuel cells, a secondary power cycle can be driven by the recuperation of exhaust gas heat. Microchannel recuperators are attractive for waste heat recuperation due to compact form factors which also minimize the mass of the expensive superalloys required. This paper introduces a...
A model has been developed to predict the long-term
oxidation rate of Zircaloy-4 for ex-reactor (autoclave) and
in-reactor (PWR) environments and operating conditions. A
computer program has been written to solve the oxygen
diffusion equation by employing a fully implicit finite
difference method for a one dimensional cylindrical
geometry. The...
Algorithms for analyzing laser interferometry
signals were developed and adopted to the computer based
processing of small displacement measurements. These
methods, matrix operation approach and fixed parameters
approach, are based on signal phase calculation and are
able to replace complex fringe counting electronic
circuits. The matrix operation provides an approach...
In 2008, the Oregon State TRIGA® Reactor (OSTR) was converted from highly-enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the...
The compressive behavior of continuous fiber composites is not as well
understood as their tensile behavior because research and industrial applications have until
recently focused on the latter. Furthermore, most theoretical and experimental studies on
the compression of composites have examined the case of unidirectional specimens with
fibers along the...
The problem of determining whether a crack impinging on an interface will penetrate into the substrate or deflect along the interface is vital to the effective design of layered and composite material systems. Of particular interest is the transition between crack propagation by penetration through an interface and deflection along...
A first generation, one-dimensional predictive model is proposed for designing heat sinks with fractal flow networks. A three-dimensional computational fluid dynamics (CFD) model is analyzed as a means for validating the model and identifying areas for improvement. Two separate CFD models were developed. One was analyzed with conjugate heat transfer...
Pure aluminum deformed in torsion (shear) at elevated temperatures reaches
a broad "peak" stress and then undergoes about a 17% decrease in flow stress with
deformation to roughly 1-2 equivalent uniaxial strain. Beyond this strain the flow
stress is approximately constant. The sources for this softening are unclear. The
suggested...
Novel ternary graphite intercalation compounds (GICs) of alkali metal cations
and a wide variety of amines have been synthesized by one-pot chemical syntheses.
Alkali metals studied includes Li, Na and K. The families of amines employed are nalkylamines,
branched alkylamines, and different structural isomers of diamines and
polyamines. Intragallery structures...
Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites may be released into the surrounding seawater and could inhibit primary production. On the other hand, some phytoplankton can use...