Index Catalog // ScholarsArchive@OSU

An efficient frequency controlled PFM for DC-DC converters

Creator:: Pai, Jeff
Abstract:: As more features are being integrated into mobile platforms, the demand for long battery life during standby mode has been increasing. Light load efficiency becomes one of essential features in today's DC-DC converter. The most effective method to improve light load efficiency is to operate the DC-DC converter under pulse-frequency-modulation...
Resource Type:: Masters Thesis

An enhanced swing differential Colpitts CMOS VCO for low-voltage operation

Creator:: Farahbakhshian, Farhad
Abstract:: An enhanced swing differential Colpitts VCO (ESDC-VCO) dramatically improves the swing of a Colpitts VCO by allowing the signal to swing below ground and above the supply voltage. Fabricated in a 1P8M 0.13 um CMOS process, the ESDC-VCO operates at 4.9GHz with a 0.475-V supply and consumes 2.7mW. The measured...
Resource Type:: Masters Thesis

An experimental study on tensile properties of cellulose nanocrystal reinforced epoxy nanocomposite material

Creator:: Zeng, Jin
Abstract:: Epoxy resin is a thermosetting resin that is commonly used as composite matrix. Epoxy composite materials are well utilized in industries, such as aerospace, due to their good mechanical properties. Nano-scale filler reinforced polymer composite materials have been intensively researched in recent decades. Cellulose nanocrystals (CNXLs) are a type of...
Resource Type:: Masters Thesis

An investigation of transition from penetration to deflection in the fracture of bi-material interfaces

Creator:: Strom, Joshua L.
Abstract:: 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...
Resource Type:: Masters Thesis

Comparison of HEU and LEU neutron spectra in irradiation facilities at the Oregon State TRIGA® reactor

Creator:: Schickler, Robert
Abstract:: 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...
Resource Type:: Masters Thesis

Computational Fluid Dynamics Modeling of the Density Evolution Inside of the Helium-3 Enhanced Negative Reactivity Insertion (HENRI) System

Creator:: Balderrama Prieto, Silvino Alejandro
Abstract:: 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...
Resource Type:: Masters Thesis

Deletions and Insertions of the Symbol 0 and Asymmetric/Unidirectional Error Control Codes for the L₁ Metric

Creator:: Alqwaifly, Nawaf
Abstract:: 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...
Resource Type:: Dissertation

Design of Compact Passive Components and Circuits for RF and Millimeter-Wave Integrated Circuit in Silicon

Creator:: Dong, Xuanyi
Abstract:: 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...
Resource Type:: Dissertation

Development and characterization of novel hydrogels for nucleus pulposus replacement

Creator:: Bader, Rebecca A.
Abstract:: Hydrogels have been proposed as candidates for nucleus pulposus replacement due to their similarity in mechanical behavior to the native tissue when subjected to transient or static loading; however, given the viscoelastic nature of soft biological tissues, the lack of dynamic testing is a significant inadequacy in the studies performed...
Resource Type:: Dissertation

Development of an economical high temperature microchannel recuperator for solid oxide fuel cells

Creator:: Brannon, Samuel T.
Abstract:: 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...
Resource Type:: Masters Thesis

Development of continental magmatic systems : insights from amphibole chemistry of the Altiplano Puna Volcanic Complex, Central Andes

Creator:: Abot, Manggon
Abstract:: The pressure history of a continental magmatic system can be deciphered by analyzing the composition of amphiboles in the eruptive products where the pressure of equilibration correlates with the depth of the magmatic system. This can reveal vertical evolution of the magma as amphibole composition varies significantly with temperature and...
Resource Type:: Masters Thesis

Development of high efficiency solar absorbers

Creator:: Ravichandran, Ram
Abstract:: 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....
Resource Type:: Dissertation

Development of new high-temperature piezoelectric perovskite ceramics

Creator:: Ansell, Troy Youngmin
Abstract:: 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...
Resource Type:: Dissertation

Discrete trap modeling of thin-film transistors

Creator:: Yerubandi, Ganesh Chakravarthy
Abstract:: A discrete trap model is developed and employed for elucidation of thin-film transistor (TFT) device physics trends. An attractive feature of this model is that only two model parameters are required, the trap energy depth, E[subscript T], and the trap density, N[subscript T]. The most relevant trends occur when E[subscript...
Resource Type:: Masters Thesis

Dynamic and Dual Streaming Methods for H.264 Video and Parallel Performance Modeling

Creator:: Johnson, Taylor N.
Abstract:: 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...
Resource Type:: Dissertation

Ecology of Greenland halibut (Reinhardtius hippoglossoides) during the early life stages in the Eastern Bering Sea and Aleutian Islands

Creator:: Sohn, Dongwha
Abstract:: Greenland halibut (Reinhardtius hippoglossoides) have decreased in the eastern Bering Sea and Aleutian Islands since the 1970s. The reasons behind the poor recruitment are unknown, and important knowledge gaps of the ecology of the early life stages have been identified. The objectives of thesis research were (1) to examine geographic...
Resource Type:: Masters Thesis

Effect of Imprinting Process on Fracture Behavior of a Zr-based Bulk Metallic Glass

Creator:: Li, Bosong
Abstract:: 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...
Resource Type:: Masters Thesis

Effects of doping, cation stoichiometry, and the processing conditions on the dielectric properties of high-K CaCu₃Ti₄O₁₂ ceramics

Creator:: Kwon, Seunghwa
Abstract:: Since its discovery, the anomalous dielectric behavior of CaCu₃Ti₄O₁₂ (CCTO) has drawn a great deal of attention for many possible applications in electronic devices. The origin of the giant dielectric constant in CCTO was explained via an internal barrier layer capacitor model, and it has been reported that the dielectric...
Resource Type:: Dissertation

Electronic Properties of Passive Films on Carbon Steel Rebar in Simulated Concrete Pore Solutions

Creator:: Williamson, Jon W.
Abstract:: 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...
Resource Type:: Masters Thesis

Energy Harvesting and Power Management Integrated Circuits for Self-Sustaining Wearables

Creator:: Bose, Soumya
Abstract:: 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...
Resource Type:: Dissertation

Evaluation of Abaqus for simulating quasi-static Mode III shear of edge notched carbon fiber reinforced polymer panels

Creator:: Hyder, Imran
Abstract:: 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...
Resource Type:: Masters Thesis

Examining Wave Attenuation Rates and Subsurface Pore Pressures Across Three Marsh Restoration Sill Structures on a Sandy Bed

Creator:: Converse, Jordan D.
Abstract:: 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...
Resource Type:: Masters Thesis

Excited state molecular structural evolution and chemical reactivity studied by femtosecond stimulated Raman spectroscopy

Creator:: Han, Fangyuan
Abstract:: 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...
Resource Type:: Dissertation

Exploratory Studies Within the Exotic Lyonsite Structure

Creator:: Tang, Joseph N.
Abstract:: 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...
Resource Type:: Dissertation

Exploring IMU Attitude and Position Estimation for Improved Location in Indoor Environments

Creator:: Zhang, Shengkai
Abstract:: 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...
Resource Type:: Masters Thesis

Fabrication and characterization of thin-film transistor materials and devices

Creator:: Hong, David
Abstract:: A class of inorganic thin-film transistor (TFT) semiconductor materials has emerged involving oxides composed of post-transitional cations with (n-1)d¹⁰ns⁰ (n≥4) electronic configurations. This thesis is devoted to the pursuit of topics involving the development of these materials for TFT applications: Deposition of zinc oxide and zinc tin oxide semiconductor layers...
Resource Type:: Dissertation

Failure analysis of pre-notched composite laminated plates under four-point bending conditions

Creator:: Arias Gonzales, Sergio
Abstract:: Ever since composite laminate technology was introduced into the aerospace and automotive industry, there has been a need to fully understand the damage progression experienced by composite laminated plates in the presence of a notch. While numerous research studies have been conducted on this matter when subjected to in-plane loads,...
Resource Type:: Dissertation

Graphite intercalation with fluoroanions by chemical and electrochemical methods

Creator:: Özmen Monkul, Bahar
Abstract:: New acceptor-type graphite intercalation compounds (GICs) containing perfluoroalkyl anions have been synthesized by using both chemical and electrochemical methods and characterized by elemental and thermogravimetric analyses. Investigation into these graphite intercalation compounds can provide novel materials and a detailed understanding of their properties. GICs of composition Cx[FB(C₂F₅)₃]·δF are prepared for...
Resource Type:: Dissertation

High-performance Ring Amplifier based Analog-to-Digital Converters

Creator:: Hu, Hang
Abstract:: 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...
Resource Type:: Dissertation

Indoor Localization Using Direction of Arrival Approach

Creator:: Zhang, Tingwei
Abstract:: 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...
Resource Type:: Masters Thesis

Influence of subset size, shape and orientation on texture based digital image correlation

Creator:: Cui, Jianqing
Abstract:: 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...
Resource Type:: Masters Thesis

Influences of Replacing Cr with Mo in Fe25Co25Ni25Cr25-XMoX High Entropy Alloy Series on the Microstructure and Mechanical Properties

Creator:: Xu, Yifan
Abstract:: 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,...
Resource Type:: Masters Thesis

Information theoretic approach to quantization and classification for signal processing, communications, and machine learning applications

Creator:: Thuan Nguyen D.
Abstract:: 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...
Resource Type:: Dissertation

Leveraging Multiple Transmissions and Receptions for Channel-Agnostic Wireless Device Identification

Creator:: Basha, Nora
Abstract:: 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...
Resource Type:: Masters Thesis

Mechanical Behavior of Elastomer Polymer under Shear and Compression: Experimental Investigation Using Digital Image Correlation

Creator:: Raheem, Hassan M.
Abstract:: 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...
Resource Type:: Dissertation

Mental Models of Mere Mortals with Explanations of Reinforcement Learning

Creator:: Anderson, Andrew A.
Abstract:: 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...
Resource Type:: Masters Thesis

Multiple Nonlinear Model Predictive Control for a Six-body System Oscillating Water Column Wave Energy Converters Array

Creator:: Xu, Zhicheng
Abstract:: 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...
Resource Type:: Masters Thesis

New Architectures and Circuits for Pushing the Dynamic Range and Multiplexing Boundaries of CMOS-Integrated Sensors

Creator:: Ouh, Hyunkyu
Abstract:: 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...
Resource Type:: Dissertation

New Insights into Mantle Dynamics from Helium Isotopes and Argon Geochronology

Creator:: Konrad, Kevin
Abstract:: 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...
Resource Type:: Dissertation

New luminescent materials and high-performance solution-processed oxide thin films

Creator:: Jiang, Kai
Abstract:: Crystals of an incongruent-melting compound, Ba₃MgSi₂O₈, were grown by the flux method and its structure was determined by single crystal X-ray diffraction methods. Ba₃MgSi₂O₈ crystallizes in trigonal space group P-3[bar]m1 with a = 5.6123(3) Å, c = 7.2667(9) Å and Z = 1. Eu²⁺ ions prefer one crystallographic Ba site...
Resource Type:: Dissertation

Non Newtonian viscosity of bulk metallic glass forming liquids and the ordering and shear rate induced crystallization of undercooled Zr₄₁.₂Ti₁₃.₈Cu₁₂.₅Ni₁₀.₀Be₂₂.₅ metallic glass forming melt

Creator:: Wadhwa, Prashant
Abstract:: The influence of shear rate and temperature on the viscosity and fragility of the Zr₄₁.₂Ti₁₃.₈Cu₁₂.₅Ni₁₀.₀Be₂₂.₅ (Vit1) metallic glass forming liquid is measured in the liquid and undercooled liquid state between 907 and 1300 K. The results show a complex rheological behavior of Vit1. The viscosity of Vit1 is about three...
Resource Type:: Dissertation

Novel ternary graphite intercalation compounds of alkali metal cations and amines

Creator:: Maluangont, Tosapol
Abstract:: 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...
Resource Type:: Dissertation

Nucleation Inhibiting Mechanisms in Atomic Layer Deposition of Nanolaminates

Creator:: Witsell, Shane Mike’ele Williama
Abstract:: 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...
Resource Type:: Masters Thesis

PAPR Reduction of Optical OFDM Systems with Exponential Companding Transform and Zero Padding

Creator:: Chen, Deyan
Abstract:: 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...
Resource Type:: Masters Thesis

Plasma-Jet Printing and In Situ Sintering of Electronic Materials for Flexible Hybrid Electronic Applications

Creator:: Manzi, Jacob
Abstract:: 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....
Resource Type:: Dissertation

Plasmonic Nano-Antenna and Modulator for On-Chip Optical Interconnects

Creator:: Gao, Qian
Abstract:: 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...
Resource Type:: Dissertation

Printing 3D Magnetic Composite Structures with Arbitrary Anisotropy using UV-curable Magnetic Ink

Creator:: Clay, Garrett
Abstract:: 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...
Resource Type:: Masters Thesis

Productive Interactions in a Complex Engineering Project: Influence of Team Members, Engineering Practice, and Emergence of Roles

Creator:: Chindanon, Kritsa
Abstract:: 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...
Resource Type:: Dissertation

Prompt gamma neutron activation analysis of niobium for characterization of light interstitials

Creator:: Love, Ian J.
Abstract:: 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...
Resource Type:: Masters Thesis

Routerless Network-on-chip

Creator:: Alazemi, Fawaz
Abstract:: 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,...
Resource Type:: Dissertation

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