Engineering Commons^™

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Efficient Private Information Retrieval, Konstantinos Nikolopoulos

Dissertations, Theses, and Capstone Projects

A vast amount of today's Internet users' on line activities consists of queries to various types of databases. From traditional search engines to modern cloud based services, a person's everyday queries over a period of time on various data sources, will leave a trail visible to the query processor, which can reveal significant and possibly sensitive information about her. Private Information Retrieval (PIR) algorithms can be leveraged for providing perfect privacy to users' queries, though at a restrictive computational cost. In this work, we consider today's highly distributed computing environments, as well as certain secure-hardware devices, for optimizing existing PIR …

Fashion Merchandising: An Augmented Reality, Naeha A. Sayed

Dissertations, Theses, and Capstone Projects

There is a continuous and constant transformation in the field of Augmented Reality (AR), both in the Retail, and the Manufacturing sector. It has started to influence everything from fashion runway shows to online shopping. Consumers dynamics have shifted in the fashion industry, the ways becoming more dominant than the old observant ones- the simple buying experience no longer satisfies them. Due to the emergence of the new digital platforms and technological enhancements, the consumers are looking for more- be it a more exciting buying experience or more user interaction or more enhanced products. This technological change starts with the …

A Purely Defeasible Argumentation Framework, Zimi Li

Dissertations, Theses, and Capstone Projects

Argumentation theory is concerned with the way that intelligent agents discuss whether some statement holds. It is a claim-based theory that is widely used in many areas, such as law, linguistics and computer science. In the past few years, formal argumentation frameworks have been heavily studied and applications have been proposed in fields such as natural language processing, the semantic web and multi-agent systems. Studying argumentation provides results which help in developing tools and applications in these areas. Argumentation is interesting as a logic-based approach to deal with inconsistent information. Arguments are constructed using a process like logical inference, with …

Using Transfer Learning In Network Markets, Kai Cai

Dissertations, Theses, and Capstone Projects

Mechanism design is the sub-field of microeconomics and game theory, which considers agents have their own private information and are self-interested and tries to design systems that can produce desirable outcomes. In recent years, with the development of internet and electronic markets, mechanism design has become an important research field in computer science. This work has largely focused on single markets. In the real world, individual markets tend to connect to other markets and form a big “network market”, where each market occupies a node in the network and connections between markets reflect constraints on traders in the markets. So, …

Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo

Dissertations, Theses, and Capstone Projects

We explore low-cost solutions for efficiently improving the 3D pose estimation problem of a single camera moving in an unfamiliar environment. The visual odometry (VO) task -- as it is called when using computer vision to estimate egomotion -- is of particular interest to mobile robots as well as humans with visual impairments. The payload capacity of small robots like micro-aerial vehicles (drones) requires the use of portable perception equipment, which is constrained by size, weight, energy consumption, and processing power. Using a single camera as the passive sensor for the VO task satisfies these requirements, and it motivates the …

Service Quality Assessment For Cloud-Based Distributed Data Services, Arun Adiththan

Dissertations, Theses, and Capstone Projects

The issue of less-than-100% reliability and trust-worthiness of third-party controlled cloud components (e.g., IaaS and SaaS components from different vendors) may lead to laxity in the QoS guarantees offered by a service-support system S to various applications. An example of S is a replicated data service to handle customer queries with fault-tolerance and performance goals. QoS laxity (i.e., SLA violations) may be inadvertent: say, due to the inability of system designers to model the impact of sub-system behaviors onto a deliverable QoS. Sometimes, QoS laxity may even be intentional: say, to reap revenue-oriented benefits by cheating on resource allocations and/or …

Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li

Dissertations, Theses, and Capstone Projects

For the first-time sulfur-doped, nitrogen-doped and sulfur, nitrogen-codoped nanoporous carbons were systematically studied as catalysts for CO₂ electrochemical reduction reaction (CO₂ERR). The Faradaic efficiencies (FE) of CO and CH₄ formation were calculated to evaluate the performance of these carbons. The best catalysts showed the FE of CO and CH₄ formation of 29% and 0.76%, respectively. It was found that the overall performance in CO₂ERR dramatically increased upon the reduction pretreatment of the carbons in N₂-saturated electrolyte before the CO₂ reduction process. The pretreated carbon showed the maximum FE of CO …

Collaborative Appearance-Based Place Recognition And Improving Place Recognition Using Detection Of Dynamic Objects, Juan Pablo Munoz

Dissertations, Theses, and Capstone Projects

This dissertation makes contributions to the problem of Long-Term Appearance-Based Place Recognition. We present a framework for place recognition in a collaborative scheme and a method to reduce the impact of dynamic objects on place representations. We demonstrate our findings using a state-of-the-art place recognition approach.

We begin in Part I by describing the general problem of place recognition and its importance in applications where accurate localization is crucial. We discuss feature detection and description and also explain the functioning of several place recognition frameworks.

In Part II, we present a novel framework for collaboration between agents from a pure …

Vision-Based Assistive Indoor Localization, Feng Hu

Dissertations, Theses, and Capstone Projects

An indoor localization system is of significant importance to the visually impaired in their daily lives by helping them localize themselves and further navigate an indoor environment. In this thesis, a vision-based indoor localization solution is proposed and studied with algorithms and their implementations by maximizing the usage of the visual information surrounding the users for an optimal localization from multiple stages. The contributions of the work include the following: (1) Novel combinations of a daily-used smart phone with a low-cost lens (GoPano) are used to provide an economic, portable, and robust indoor localization service for visually impaired people. (2) …

Nonlinear Optical Studies Of Defects And Domain Structures In Perovskite-Type Dielectric Ceramics, David J. Ascienzo

Dissertations, Theses, and Capstone Projects

In order to improve future generations of dielectric capacitors a deeper understanding of voltage-induced dielectric breakdown and electrical energy storage limitations is required. This dissertation presents the use of far-field optical second harmonic generation (SHG) polarimetry for probing structural defects and polar domains in linear and nonlinear perovskite dielectric ceramics. We investigated the formation of electric field-induced structural distortions at pristine Fe-doped SrTiO₃ (Fe:STO) electrode interfaces, structural defect and strain formation due to oxygen vacancy migration in electrodegraded Fe:STO single crystals, and mixed tetragonal and rhombohedral phase domains in ferroelectric Zr-doped BaTiO₃ (BZT) films exhibiting excellent …

In Search Of Homo Sociologicus, Yunqi Xue

Dissertations, Theses, and Capstone Projects

The subject of this dissertation is to build an epistemic logic system that is able to show the spreading of knowledge and beliefs in a social network that contains multiple subgroups. Epistemic logic is the study of logical systems that express mathematical properties of knowledge and belief. In recent years, there have been increasing number of new epistemic logic systems that are focused on community properties such as knowledge and belief adoption among friends.

We are interested in revisable and actionable social knowledge/belief that leads to a large group action. Instead of centralized coordination, bottom-up approach is our focus. We …

Mutagenesis Of Human Alpha-Galactosidase A For The Treatment Of Fabry Disease, Erin Stokes

Dissertations, Theses, and Capstone Projects

Fabry disease is an X-linked lysosomal storage disorder caused by the deficiency of the enzyme, α-galactosidase A, which results in the accumulation of the lipid substrate. This accumulation results in obstruction of blood flow in patients and early demise at approximately 40-60 years of age. There is currently only one FDA approved treatment (Fabrazyme) classified as an enzyme replacement therapy. However, approximately 88% of patients experience a severe immune response that, rarely, can be fatal and is a huge cost burden at average $250,000 a year per patient. The structure of α-galactosidase A has been previously determined to be a …

Removal Of Organic Micro-Pollutants From Water Using Sewage Sludge Based Composite Adsorbents, Rui Ding

Dissertations, Theses, and Capstone Projects

Millions of tons of sewage sludge, waste oil sludge and fish waste are produced annually, and improper treatment/disposal of these wastes have resulted in numerous environmental issues. On the other hand, these wastes are rich in organic materials, metals, and inorganic minerals and could be sustainable resources if utilized properly. The main purpose of this dissertation study was, therefore, to convert these wastes into composite adsorbents, and then use these adsorbents to remove various types of organic pollutants, emerging organic contaminants in particular, from wastewater and drinking water sources.

It is hypothesized that a hydrophobic carbon phase in the composite …

Mechanotransduction Modulates The Effect Of Mechanical Forces (Fluid Shear Stress And Cyclic Strain) On Embryonic Stem Cell Differentiation Toward Vascular Endothelial Cells, Maria Nikmanesh

Dissertations, Theses, and Capstone Projects

The isolation of human ES cells (hES) in 1998 remarkably elevated the interest in the cell therapy capability of ES cells and moved this concept one step closer to reality. Embryonic stem cells with their potential for both self-renewal and directed differentiation have received increasing attention in applications in tissue engineering and repair, cell therapy, and regenerative medicine.

The differentiation of embryonic stem cells into desired lineages depends on the chemical environment of the “niche”, and for certain lineages such as the vascular lineage that must function in a mechanical environment, the timely imposition of mechanical forces is critical. In …

Guidance Index For Shallow Landslide Hazard Analysis, Cheila Cullen

Dissertations, Theses, and Capstone Projects

Rainfall-induced landslides are one of the most frequent hazards on slanted terrains. They lead to considerable economic losses and fatalities worldwide. Intense storms with high-intensity and long-duration rainfall have high potential to trigger rapidly moving soil masses due to changes in pore water pressure and seepage forces. Nevertheless, regardless of the intensity-duration of the rainfall, shallow landslides are influenced by antecedent soil moisture conditions. To the present day, no system exists that dynamically interrelates these two factors.

This work establishes a relationship between antecedent soil moisture and rainfall expressed in the form of a Shallow Landslide Index (SLI) at 1km …

Vector Beams For Fundamental Physics And Applications, Giovanni Milione

Dissertations, Theses, and Capstone Projects

Lights salient degrees of freedom are the independent parameters that completely de- scribe an electromagnetic wave (in the paraxial approximation) and include polarization, wavelength, and time. Most recently, lights space degree of freedom has received sig- nificant attention via the sub-discipline of optics that can be referred to as complex light or structured light. The study of complex light is a veritable renaissance of optics; us- ing lights space degree of freedom many classical optics phenomena have been revisited with novel results. In this thesis, a novel form of structured light referred to as vector beams will be investigated. It …

The Design, Fabrication And Characterization Of Integrated Photoconductive Antennas For On-Chip Terahertz Wave Radiation And Detection, Ruben Dario Velasquez Rios

Dissertations, Theses, and Capstone Projects

Terahertz (THz) wave (between 0.1 and 10 THz) is attracting a lot of attention due to its unique properties that are favorable to various applications. These include non-ionizing radiation, better resolution than a microwave, unique spectral absorption, and an ability to propagate through many types of materials. It has been intensively researched in sensing and imaging technology for a wide range of applications in areas such as biology, pharmaceutical, food and drug control, medical science, and security screening. Driven by mostly scientific research interests, the majority of THz systems are more focused on system performance rather than system size, integration, …

Scale Up Bayesian Network Learning, Xiannian Fan

Dissertations, Theses, and Capstone Projects

Bayesian networks are widely used graphical models which represent uncertain relations between the random variables in a domain compactly and intuitively. The first step of applying Bayesian networks to real-word problems is typically building the network structure. Optimal structure learning via score-and-search has become an active research topic in recent years. In this context, a scoring function is used to measure the goodness of fit of a structure to given data, and the goal is to find the structure which optimizes the scoring function. The problem has been viewed as a shortest path problem, and has been shown to be …

Effect Of Temporal Onset Of Mechanical Loading On Tendon To Bone Healing, Determined With A Novel In-Vivo Device, Mark E. Stasiak

Dissertations, Theses, and Capstone Projects

Background: Exposure to tensile loading has been shown to maintain tendon/ligament homeostasis, with the tensile modulus of the tissue increasing in response to greater loading frequency, and even decreasing in the absence of load. However after injury or surgical repair the effect of tensile load is controversial, with many studies implicating mechanical loading with impaired healing. It is currently unknown when the tensile loading imparted during rehabilitation exercise, can be safely reintroduced after surgical tendon repair or ligament reconstruction, and at what time point it can most benefit the remodeling process. To investigate the effect of tensile loading protocols on …

Zncdmgse As A Materials Platform For Advanced Photonic Devices: Broadband Quantum Cascade Detectors And Green Semiconductor Disk Lasers, Joel De Jesus

Dissertations, Theses, and Capstone Projects

The ZnCdMgSe family of II-VI materials has unique and promising characteristics that may be useful in practical applications. For example they can be grown lattice matched to InP substrates with lattice matched bandgaps that span from 2.1 to 3.5 eV, they can be successfully doped n-type, have a large conduction band offset (CBO) with no intervalley scattering present when strained, they have lower average phonon energies, and the InP lattice constant lies in the middle of the ZnSe and CdSe binaries compounds giving room to experiment with tensile and compressive stress. However they have not been studied in detail for …

Water Condensation And Protein Adsorption On Hybrid Superhydrophobic-Hydrophilic Surfaces, Bikash Mondal

Dissertations, Theses, and Capstone Projects

This thesis describes the study of protein adsorption and water condensation on hybrid superhydrophobic-hydrophilic surfaces for various technological applications such as diagnostics, artificial organs and medical devices, water collection, and heat transfer.

In the chapter 1, a general introduction to wetting theories, superhydrophobic surface, and hybrid surfaces is given. In chapter 2, design and fabrication of a hybrid superhydrophobic surface for studying dropwise condensation and heat transfer is discussed. Effect of surface chemistry and wettability on protein adsorption is discussed in the chapter 3. Finally, in chapter 4, the protein adsorption study on hybrid superhydrophobic surfaces made by 3D-printing and …

3d Scene Reconstruction With Micro-Aerial Vehicles And Mobile Devices, Ivan Dryanovski

Dissertations, Theses, and Capstone Projects

Scene reconstruction is the process of building an accurate geometric model of one's environment from sensor data. We explore the problem of real-time, large-scale 3D scene reconstruction in indoor environments using small laser range-finders and low-cost RGB-D (color plus depth) cameras. We focus on computationally-constrained platforms such as micro-aerial vehicles (MAVs) and mobile devices. These platforms present a set of fundamental challenges - estimating the state and trajectory of the device as it moves within its environment and utilizing lightweight, dynamic data structures to hold the representation of the reconstructed scene. The system needs to be computationally and memory-efficient, so …

Seismic Fragility Analysis For Highway Bridges With Consideration Of Soil-Structure Interaction And Deterioration, Xin Zong

Dissertations, Theses, and Capstone Projects

Bridges are critical elements within the highway transportation network. It is very important for the owner or designer to perform the risk assessment of the highway bridges during extreme events, such as earthquakes, due to their importance to the network, commerce, economic vitality and mobility. Recent studies show that seismic fragility curves are useful tools for the seismic risk assessment of highway bridges.

Although general seismic fragility approach has been well established in the last two decades and numerous retrofit methods have been applied to highway bridges in New York City (NYC) metropolitan area, which has been classified as moderate …

Development Of Functional Interactions Among Cortical And Trabecular Traits During Growth Of The Lumbar Vertebral Body, Melissa Ramcharan

Dissertations, Theses, and Capstone Projects

Variation in bone traits that contribute to increased fracture risk in the elderly is mainly established in adulthood. Previous studies have shown that in adults, cortical and trabecular traits are functionally related. How variations in traits develop to establish mechanical function in adult bone is not well understood. In this study, we examined temporal changes in the development of cortical and trabecular traits during growth in mouse lumbar vertebral body structures that have a wide range of genetic variants. We determined a sequence of events among traits that would suggest how functional bone structures developed. Examining bones in A/J, C57/BL6 …

Highly-Selective Chemiresistive Sensing And Analysis Of Vapors Using Functionalized Nanotubes, Deon Hines

Dissertations, Theses, and Capstone Projects

Specifically, the project involves the development of a diversified array of nanostructured gas-sensors comprised of selectively, novel surface-functionalized carbon nanotubes (for analyte selectivity by virtue of functionality). Harnessing carbon nanotubes with various electron withdrawing and donating groups help in determining their affinity toward certain prognostic gaseous markers thus increasing specificity of such created sensors. We have devised synthetic routes that have led to the facile production of covalently polyfunctionalized nanotubes in high yield. Seven carbon nanotube analogues were systematically considered and then chemically synthesized, from pristine single-walled nanotubes (SWNT's), for use as the main component of sensory units that was …

Label-Free Detection Of Cancer Cells With Polysilicon Sensor Chips And Biomolecule-Assisted Synthesis Of Shape-Controlled Nanoparticles, Menglu Shi

Dissertations, Theses, and Capstone Projects

Constant effort has been made for the detection of cancer cells. Recently, ovarian and kidney cancer cell lines have been shown to have higher cellular elasticity as compared to normal cells assessed by monitoring the degree of deformation under hyposmotic pressure. This method has been modified and applied to various cases. In cancer cells, the oncogenic mutant p53 (mtp53) protein is present at high levels and contributes to tumor growth and metastasis. Herein the influence of mtp53 on the mechanical property of breast cancer cells was assessed by monitoring the swelling ratio of cells with time using the impedance measurements. …

Synthesis And Characterization Of A Novel Polyacetal & Design And Preparation Of Superhydrophobic Photocatalytic Surfaces, Yuanyuan Zhao

Dissertations, Theses, and Capstone Projects

Polyacetal polymers are thermoplastic resins that play an important role in industry because of numerous industrial applications including automobile; household appliance; etc. The first part of this thesis (Chapter 2) is about the synthesis of a new acetal copolymer that exhibits superior thermal stability. The second part of this thesis (Chapter 3) is about the preparation and applications of TiO₂-based polymer nanocomposite films, where the reactive oxygen species (ROS) are generated on the solid surface. Catalytic nanocomposite films are an active area of research because of their potential uses for environmental remediation and chemical synthesis. Furthermore, to …

Estimation Of Outer-Middle Ear Transmission Using Dpoaes And Fractional-Order Modeling Of Human Middle Ear, Maryam Naghibolhosseini

Dissertations, Theses, and Capstone Projects

Our ability to hear depends primarily on sound waves traveling through the outer and middle ear toward the inner ear. Hence, the characteristics of the outer and middle ear affect sound transmission to/from the inner ear. The role of the middle and outer ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea, and recorded by a sensitive microphone placed in the ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and middle ear characteristics. To …

Biomolecule Mediating Synthesis Of Inorganic Nanoparticles And Their Applications, Zengyan Wei

Dissertations, Theses, and Capstone Projects

Project 1.

The conventional phage display technique focuses on screening peptide sequences that can bind on target substrates, however the selected peptides are not necessary to nucleate and mediate the growth of the target inorganic crystals, and in many cases they only show moderate affinity to the targets. Here we report a novel phage display approach that can directly screen peptides catalytically growing inorganic nanoparticles in aqueous solution at room temperature. In this study, the phage library is incubated with zinc precursor at room temperature. Among random peptide sequences displayed on phages, those phages that can grow zinc oxide (ZnO) …