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Modeling And Control Of Probe-On-Probe Dynamics In Dual-Probe Atomic Force Microscopy, Ayad Al-Ogaidi

Doctoral Dissertations

“The atomic force microscope (AFM) is a widely used instrument for imaging and direct manipulation of materials and particles at the nanoscale. The AFM uses a probe, which is a microcantilever with a sharp point at the end. Typically, the AFM is constructed with a single probe. The disadvantage of this construction is that it can only be used either for imaging or manipulation in one implementation. An AFM was constructed using two probes, permitting simultaneous imaging and manipulation. A dual-probe AFM (DP-AFM) provides a foundation for feedback controlled manipulation.

Paper I investigates probe-on-probe contact stability and examines the dynamics …

Facile Synthesis Of Nanostructured Metal Borides And Composites For Applications In Sustainable Energy, Maalavan Arivu

Masters Theses

"Electrocatalytic water splitting is a promising solution for sustainable energy generation since one of the half reactions lead to the formation of H₂ which is a clean fuel. The other half of the reaction leading to O₂ evolution is an energy intensive process necessitating the need for an electrocatalyst to break the activation barrier for the commencement of the reaction. In this work we will focus on expanding the family of non-oxidic OER electro-catalysts, especially borides, whereby, apart from facilitating delocalization of electron cloud on the catalytically active transition metal site, low anion electronegativity and increased covalency in …

Development And Monte Carlo Validation Of A Finite Element Reactor Analysis Framework, Wayne J. Brewster

Masters Theses

"This study presents the development and Monte Carlo validation of a continuous Galerkin finite element reactor analysis framework. In its current state, the framework acts as an interface between the mesh preparation software GMSH and the sparse linear solvers in MATLAB, for the discretization and approximation of 1-D, 2-D, and 3-D linear partial differential equations. Validity of the framework is assessed from the following two benchmarking activities: the 2-D IAEA PWR benchmark; and the 2-D Missouri Science and Technology Reactor benchmark proposed within this study. The 2-D IAEA PWR multi-group diffusion benchmark is conducted with the following discretization schemes: linear, …

De-Embedding Method Comparisons And Physics Based Circuit Model For High Frequency D-Probe, Yuan Chen

Masters Theses

"In section 1, the procedures of 1X-Reflect smart fixture de-embedding (SFD), 1-port auto fixture removal (AFR), and 2X-Thru SFD are compared from various perspectives: test fixture design, the de-embedding procedure, and de-embedded results. The accuracy of fixture characterization and the de-embedded result is the key figure of merit (FOM) in each de-embedding method. Full wave models are built to evaluate the FOM of the three methods, by comparing the scattering parameters (S-parameters) and time domain reflectometer (TDR). A test coupon for measuring USB-C cables is adopted to serve as a manufactured validation purpose.

In section 2, a physics-based circuit model …

Bioaccessibility Of Lead From Contaminated Soil Using Phosphate Treatment -- Physiologically Based Extraction Test And In Vitro Gastrointestinal Method Test, Austin Charles Doss

Masters Theses

"Phosphate treatments are used to immobilize lead in soil by forming pyromorphite. Soil from Bonne Terre, Mo was collected to study whether such treatment decreases the bioaccessibility of lead. The soil was treated using 0.5 soil wt% of phosphate. Treatments were: none, phosphoric acid, triple super phosphate, and organic bone meal. Each sample was studied after one, four, sixteen, and twenty weeks; during this time span, water was added approximating the average rainfall rate. Percolated water was collected to test the leached phosphate concentrations. Phosphate was below the detection limit in that leachate. Remediated soil samples were used in Physiologically …

Battery Optimization In Microgrids Using Markov Decision Process Integrated With Load And Solar Forecasting, Prateek Jain

Masters Theses

"Rising climatic concerns call for unconventional/renewable energy sources which reduce the carbon footprint. Microgrids that integrate a variety of renewable energy resources play a key role in utilizing these energy resources in a more efficient and environmentally friendly manner. Battery systems effectively help to utilize these energy resources more efficiently. This research work presents a framework based on Markov Decision Process (MDP) integrated with load and solar forecasting to derive an optimal charging/discharging action of Battery with rolling horizon implementation. The load forecasting regression models are discussed and developed. Also, various solar forecasting models like clear sky, multi-regression and Non-Linear …

Multiple Security Domain Non Deducibility In The Freedm Smart Grid Infrastructure, Manish Jaisinghani

Masters Theses

"The building block of today's world are not materials, but, computers and algorithms with communication networks between physical entities. A cyber physical system (CPS) is a system in which the cyber and physical entities of the system work together towards a common goal, for example a water treatment facility or an electricity distribution system. These cyber physical infrastructures affect day to day lives of people and hence become target point for the attackers to disrupt normal daily life. Owing to the complexity of a cyber physical system, the attacks have themselves become sophisticated and harder to detect. These sophisticated attacks …

Examination Of Shear Friction Design Provisions, Nikkolas J. Edgmond

Masters Theses

"This thesis reports the results of research conducted to establish a state-of-the-art database of shear-friction studies to be turned over to ACI Committee 445-0D as a living document, utilize a subset of the established database to examine the effectiveness of the ACI 318 Code (2014), PCI Design Handbook (2010), AASHTO LRFD Bridge Design Specification (2016) and CSA A23.3 Design of Concrete Structures Standard (2014) provisions to predict shear transfer strength, and examine the effective coefficient of friction (µ_e) approach allowed in the PCI Design Handbook (2010).The shear friction design concept is applicable in conditions where direct shear must …

Methodology For 3d Full-Wave Simulation Of Electrostatic Breakdown Across An Air Gap, Darwin Zhang Li

Masters Theses

"The Rompe-Weizel SPICE model is used to obtain the time dependent arc resistance during simulation of air gap discharge. The SPICE model is solved using a circuit simulator, and the accompanying 3D model is solved using the transmission-line matrix time domain numerical method. Transient co-simulation is a new technique that is used to solve both circuit and 3D models at the same time. Transient co-simulation with the Rompe-Weizel SPICE model is first validated for different arc lengths using a simple geometry of a rod discharging to a ground plane. Validation is achieved by comparing the discharge currents from simulation with …

Cloud Transactions And Caching For Improved Performance In Clouds And Dtns, Dileep Mardham

Masters Theses

"In distributed transactional systems deployed over some massively decentralized cloud servers, access policies are typically replicated. Interdependencies ad inconsistencies among policies need to be addressed as they can affect performance, throughput and accuracy. Several stringent levels of policy consistency constraints and enforcement approaches to guarantee the trustworthiness of transactions on cloud servers are proposed. We define a look-up table to store policy versions and the concept of "Tree-Based Consistency" approach to maintain a tree structure of the servers. By integrating look-up table and the consistency tree based approach, we propose an enhanced version of Two-phase validation commit (2PVC) protocol integrated …

Recycling Effect In Expanded Granular Sludge Bed Reactor And Implementation Of Six Sigma In A Methane Generation Process, Manohar Manchenahalli Shivashankaraiah

Masters Theses

"Brewery industries are the largest consumers of water among several production industries. Despite consuming these huge amounts of water and electricity, they generate by-products that are harmful to the environment. These by-products contain organic, inorganic, and solid wastes with high chemical oxygen demand (COD) strength. The anaerobic digestion (AD) process plays an important role in treating this wastewater. This study investigates the design and development of an expanded granular sludge bed reactor (EGSB) effluent recirculation, which can achieve high COD removal efficiency of the wastewater and enhance the efficiency of generating biogas with high yields and increases in the concentration …

Nonlinear Finite Element Analysis Of Concrete Columns Subjected To Complex Loading, Adam Christopher Morgan

Masters Theses

"This study details the development and implementation of a finite element model within a commercial finite element code, Abaqus CAE, for the analysis of reinforced concrete (RC) bridge columns containing interlocking spirals subjected to combined loading conditions including axial, shear, bending, and torsional loads, including the post-peak response. The model is a first of its kind attempt at simulating the response of RC columns with continuous spiral transverse reinforcement and subjected to combined loading conditions including torsion. The model is utilized to determine the quasi-static load-deformation response under various proportions of the input loads and displacements. The resulting quasi-static load-deformations, …

Transmission Line Inspection Using Suspended Robot: Cost Effective Analysis And Operational Routing Identification, Balaji Rathinam Nagarajan

Masters Theses

"High voltage transmission lines form a crucial part of the energy infrastructure of a country. Effective maintenance is required to maintain its reliability and reduce the probability of the occurrence of the outage. Conventionally, the routine inspection of the transmission line was conducted by linemen with the assistance of hot stick and helicopter, which is considered dangerous, time-consuming, and expensive.

In this thesis, we focus on the initial study of seeking the state of the art robotics technology to by largely replace human beings in transmission line inspection. The existing robotics technologies that are interested by utility companies, as well …

Management Of Coal Dust Explosions In United States' Coal Mines Using Bag Type Passive Explosion Barriers, Jay Robert Schafler

Masters Theses

"The most significant and powerful hazard that exists in an underground coal mine is a coal dust explosion. A coal dust explosion has the potential to propagate throughout a mine resulting in massive damage to the mine and equipment, as well as tragic loss of life. An assessment of current global regulations and practices uncovered four main control methods utilized to prevent coal dust explosions in coal mines world-wide. The United States is one of the few countries that does not regulate or employ all four of these safety practices. Additionally, a review of past research into coal dust explosions …

The Role Of Flexural Slip In The Development Of Chevron Folds, Yuxing Wu

Masters Theses

"Chevron folds are characterized by straight limbs and narrow hinge zones. One of the conceptual models to initiate and develop chevron folds involves flexural slip during folding. While some kinematical models show the necessity for slip to initiate during chevron folding, recent numerical modeling studies of visco-elastic effective single layer buckle folding have shown that flexural slip does not result in chevron folds. In this study, several 2D finite element analysis models are run, distinguished by 1) geometry of the initial perturbation (sinusoidal and white noise), 2) varying thewavelength of the initial perturbation (10%, 50%, and 100% of the dominant …

Grain Refinement Of High Alloy Stainless Steels In Sand And Directionally Solidified Castings, Dustin Alan Arvola

Masters Theses

"The goal of this research project is to develop an industrially viable melting process that will control the crystallization macrostructure of austenitic grades of cast steels. Titanium nitride (TiN) has proven to be an effective grain refiner of austenite. Theoretical simulation and experimental application has led to the development of a repeatable grain refining melt process for austenitic stainless steel alloys.

Grain refinement of the as-cast structure of Cr-Ni stainless steel alloys solidified with primary FCC, BCC and dual FCC/BCC phases was studied experimentally. Refinement was achieved in both cast ferritic and austenitic grades. Dual solidification of …

Developing An Energy Efficient Real-Time System, Aamir Aarif Khan

Masters Theses

"Increasing number of battery operated devices creates a need for energy-efficient real-time operating system for such devices. Designing a truly energy-efficient system is a multi-staged effort; this thesis consists of three main tasks that address different aspects of energy efficiency of a real-time system (RTS).

The first chapter introduces an energy-efficient algorithm that alternates processor frequency using DVFS to schedule tasks on cores. Speed profiles is calculated for every task that gives information about how long a task would run for and at what processor speed. We pair tasks with similar speed profiles to give us a resultant merged speed …

The Importance Of Chemical Grouting Materials For Optimum Mechanical Performance With Different Soil Conditions, Yusuf Alper Cinar

Masters Theses

"Grouting is a frequently used technique for controlling the water inflow and reinforcement of soil and rock. Even though cement-based grouting materials have been well characterized, ongoing improvements of chemical grouting materials create a need to better understand the characteristics of these materials in order to increase the efficiency of grouting applications. The purpose of this study is to characterize three common chemical grouting materials by exploring their mechanical performance under varying initial soil conditions. Performance decision criteria consist of the Unconfined Compressive Strength (UCS) and slake durability test results, observation of penetration ability, and comparison of the findings. The …

Effects Of Terrain-Based Altimetry On Navigation Performance, Kenneth Michael Kratzer

Masters Theses

"Navigation filters used during an entry, descent, and landing scenario often receive measurements related to the terrain over which the vehicle is traversing. Models of the terrain can be presented in varying degrees of fidelity, providing increasingly realistic and accurate models of the surface. While it is ideal to provide the filter with the most realistic model possible, the performance is limited by the strict nature of the real time scenario. Therefore, it is of interest to determine what level of fidelity is necessary to achieve an accurate filtering solution. Determining how best to incorporate terrain-related data into navigation solutions …

Modeling And Control Of Three-Phase Grid-Connected Pv Inverters In The Presence Of Grid Faults, Paresh Vinubhai Patel

Masters Theses

"A two-stage photovoltaic grid-connected microgrid modeling approach is presented in this work. The purpose of the modeling is the behavior study of the microgrid during the low-voltage event on the grid. A complete mathematical model is discussed for each component of the system. The MPPT of the photovoltaic system is integrated with the boost controller to inject the constant current in the DC-link. The boost converter and the inverter control is implemented using the cascaded PI control. A dual second-order generalized integrator (DSOGI) method is implemented for the sequence extraction. The inverter controller is designed to meet the grid-code requirement …

Analyzing Large Scale Trajectory Data To Identify Users With Similar Behavior, Tyler Clark Percy

Masters Theses

"In today's society, social networks are a popular way to connect with friends and family and share what's going on in your life. With the Internet connecting us all closer than ever before, it is increasingly common to use social networks to meet new friends online that share similar interests instead of only connecting with those you already know. For the problem of attempting to connect people with similar interests, this paper proposes the foundation for a Geo-social network that aims to extract the semantic meaning from users' location history and use this information to find the similarity between users. …

Precise Energy Efficient Scheduling Of Mixed-Criticality Tasks & Sustainable Mixed-Criticality Scheduling, Sai Sruti

Masters Theses

"In this thesis, the imprecise mixed-criticality model (IMC) is extended to precise scheduling of tasks, and integrated with the dynamic voltage and frequency scaling (DVFS) technique to enable energy minimization. The challenge in precise scheduling of MC systems is to simultaneously guarantee the timing correctness for all tasks, hi and lo, under both pessimistic and optimistic (less pessimistic) assumptions. To the best of knowledge this is the first work to address the integration of DVFS energy conserving techniques with precise scheduling of lo-tasks of the MC model.

In this thesis, the utilization based schedulability tests and sufficient conditions for such …

The Effects Of Privacy Violation Abstractness On Privacy Attitudes And Behaviors, Delicia Anceisao Vaz

Masters Theses

"This research investigates new methods to present privacy policy information to consumers. It makes the argument that current privacy policies do not present consumers with information in a manner that helps align their privacy attitudes with their privacy behaviors. With the introduction of smart appliances to the market, it is critical that appropriate privacy policies are created to equip consumers with information that is easy to understand. Neutral Examples and Risk Examples were created along with the Traditional Content of a privacy policy. These three components were used in different combinations to provide privacy information about smart appliances. Additionally, it …

Bridge Deck Assessment Using Visual Inspection, Ground Penetrating Radar, Portable Seismic Property Analyzer-Ultrasonic Surface Wave, Hammer Sounding And Chain Drag, Abdullah Hadi Zaid Alhaj

Masters Theses

"Integrated non-destructive techniques were utilized to assess the condition of a reinforced concrete bridge deck. There were two main objectives accomplished.

The first objective was to assess the integrity of the reinforced concrete bridge deck using four non-destructive techniques, namely visual inspection, ground penetrating radar, portable seismic property analyzer-ultrasonic surface wave, and hammer sounding and chain drag. Visual inspection data were used to identify signs of deterioration on surface of the bridge deck such as cracking, concrete leaching, and reinforcement corrosion. Ground penetrating radar data were used to determine the relative condition of the bridge deck. However, due to the …

New Nanoparticle Water-Based Drilling Fluid Formulation With Enhanced Thermal Stability And Inhibition Capabilities In The Woodford Shale, Jose Aramendiz Pacheco

Masters Theses

"Drilling fluid design for unconventional reservoirs aims at preventing formation instability problems associated with fluid invasion, shale swelling, and cuttings dispersion. Although oil-based mud (OBM) can be used to achieve these goals, environmental and economic concerns limit its application. This experimental study evaluated the potential use of nanoparticles (NP) to improve water-based mud (WBM) inhibition capabilities and its ability to enhance the overall drilling fluid thermal stability while providing a cleaner technology to the industry.

Characterization of Woodford shale was completed with X-ray diffraction, cation exchange capacity, and scanning electron microscopy, silica, and graphene NP were characterized with aqueous stability …

Developing A Methodology For Estimating The Growth Of Radiated Emission From Multi-Modular Systems, Kaustav Ghosh

Masters Theses

"The large multiscale problems are commonly faced in real-world applications such as analysis of electromagnetic interference for a printed circuit board installed on a large platform with connected cables, wires and other high speed interfaces. EMI problems are not uncommon in high speed systems which involve multiple modules of complex hardware. As the system clock frequency and data rate increases, so does the challenges in controlling the EMI in such systems. The costs to prototype and to develop networking equipment are growing as a result of increasing complexities and densities. EMC regulations require radiated emission testing to be done in …

Developing Computational Models For Pulsed-Inductive Plasma Formation, Zachary Aaron Gill

Masters Theses

"Pulsed-inductive discharges are a common method of producing a plasma. They provide a mechanism for quickly and efficiently generating a large volume of plasma for rapid use and are seen in applications including propulsion, fusion power, and high-power lasers. However, some common designs see a delayed response time due to the plasma forming when the magnitude of the magnetic field in the device is at a minimum. New designs are difficult to evaluate due to the amount of time needed to construct a new geometry and the high monetary cost of changing the power generation circuit. To more quickly evaluate …

Developing Improved Techniques For Gpr Guided Wave Data Analysis, Yunyi Guan

Masters Theses

"This study was conducted to investigate how limiting the allowable velocity range when analyzing guided wave data will affect the results of dielectric permittivity and thickness estimation. We conducted four sets of Experiments: an underlying layer of saturated organic loam is covered by incremental layers of the dry organic loam; a base layer of dry organic loam covered by the saturated organic loam; a saturated basal layer of silt with overlying dry silt layers, and a base layer of dry silt overlain by saturated silt layers to conduct a comparative study and perform three surveys for each of these three …

Compressive Behavior Of Masonry Columns Confined With Steel Reinforced Grout (Srg) Composite, Sarah Elizabeth Jemison

Masters Theses

"In this study, a new type of composite comprised of steel fiber cords embedded in a natural hydraulic lime mortar matrix, known as steel reinforced grout (SRG), is explored for the use in confinement of masonry columns. An experimental study was carried out to understand the behavior of solid clay brick masonry columns confined by SRG jackets. Twenty-four confined and seven unconfined columns with a square cross-section were tested to failure under a monotonic concentric compressive load. Test parameters considered were the column corner condition, number of fiber jacket layers, and number of fiber overlapping faces. SRG confinement improved the …

Smart Augmented Reality Instructional System For Mechanical Assembly, Ze-Hao Lai

Masters Theses

"Quality and efficiency are pivotal indicators of a manufacturing company. Many companies are suffering from shortage of experienced workers across the production line to perform complex assembly tasks such as assembly of an aircraft engine. This could lead to a significant financial loss. In order to further reduce time and error in an assembly, a smart system consisting of multi-modal Augmented Reality (AR) instructions with the support of a deep learning network for tool detection is introduced. The multi-modal smart AR is designed to provide on-site information including various visual renderings with a fine-tuned Region-based Convolutional Neural Network, which is …