Engineering Commons^™

Wind Farm Optimization Using Evolutionary Algorithms, Carlos Marco Ituarte-Villarreal

Open Access Theses & Dissertations

In recent years, the wind power industry has focused its efforts on solving the Wind Farm Layout Optimization (WFLO) problem. Wind resource assessment is a pivotal step in optimizing the wind-farm design and siting and, in determining whether a project is economically feasible or not. In the present work, three (3) different optimization methods are proposed for the solution of the WFLO: (i) A modified Viral System Algorithm applied to the optimization of the proper location of the components in a wind-farm to maximize the energy output given a stated wind environment of the site. The optimization problem is formulated …

Transition Metal Carbide (Tmc) Novel Materials For Novel Catalytic Applications, Svetlana Lagoykina

Open Access Theses & Dissertations

Transition metal carbides (TMC) constitute a diverse class of materials and traditionally have many technological applications. TMC became a subject of extensive research since 1973, when their platinum -like properties were discovered. They demonstrated high catalytical activity and selectivity in a variety of chemical reaction and have potential for some novel catalytic application.

This research is an effort to design new high effective, selective and stable bimetal or alkali promoted TMC catalyst. After extensive theoretical research a wide range of TMC, including bimetal and alkali promoted carbides, were synthesized by different methods. All solids were characterized by XRD and microscopy. …

Thermal Shock Studies On Carbon-Carbon Composites: Experimentation And Analysis, Alma Lucia Leanos

Open Access Theses & Dissertations

The oxidation behavior of C/C composites under thermal shock conditions in air is understood and predicted experimentally and by computational efforts. In Chapter. 1, both compressive properties and oxidation behavior of pristine and thermal shock exposed 2D C/C composite specimens were examined. Pristine test specimens were exposed to thermal shock conditions with temperatures ranging from 400°C to 1000°C in an oxidizing environment, followed by compression tests on pristine and thermal shock exposed specimens to obtain their compressive responses.

Similarly, in Chapter. 2, the influence of thermal shock conditions on both, the extent of carbon materials decomposition and the through-thickness compressive …

Computation Offloading Decisions For Reducing Completion Time, Salvador Melendez

Open Access Theses & Dissertations

Mobile devices are being widely used in many applications such as image processing, computer vision (e.g. face detection and recognition), wearable computing, language translation, and battlefield operations. However, mobile devices are constrained in terms of their battery life, processor performance, storage capacity, and network bandwidth. To overcome these issues, there is an approach called Computation Offloading, also known as cyber-foraging and surrogate computing. Computation offloading consists of migrating computational jobs from a mobile device to more powerful remote computing resources. Upon completion of the job, the results are sent back to the mobile device. However, a decision must be made; …

Effect Of Si Substrate Orientation On The Quality Of Cdte Selective Growth On Si(111) And Si(211) Substrates Via Closed-Space Sublimation (Css) Witout The Use Of A Mask., Aryzbe Najera

Open Access Theses & Dissertations

The material, fabrication and operation parameters for mercury cadmium telluride (HgCdTe) detectors require high sensitivity, small pixel size, low defect density, long-term thermal-cycling reliability and large area substrates. The focus of this work is on the epitaxial growth of CdTe thin films on Si(111) and Si(211) for the purpose of using the resulting material as a substrate for the subsequent growth of HgCdTe thin films. Currently, there is an interest to improve the quality of epitaxial thin films associated with the fabrication of HgCdTe infrared and X-ray imaging using the close-spaced sublimation (CSS) technique. The CSS technique is proven to …

Reliability And Sensitivity Analysis For Micro-Meteoroids And Orbital Debris Protection Models Using First-Order Reliability Methods (Form)., Levi Pereda

Open Access Theses & Dissertations

Abstract This Thesis provides a probabilistic assessment of the micro-meteoroids and orbital debris (MMOD) impact protection structures. The assessment is based on first-order reliability methods that use Ballistic Limit equations traditionally used by NASA for the design of shields. The research demonstrates how the structural reliability methods can be implemented into the aeronautics and astronautics field. NASA is continuously developing new techniques that allow the consideration of the uncertainty that exists in the design of their space structures. Nevertheless, some of their design approaches are still deterministic. For example MMOD ballistic limit equations used for the design of the MMOD …

Fluid Flow Characterization Of High Turbulent Intensity Compressible Flow Using Particle Image Velocimetry, Marco Efrain Quiroz

Open Access Theses & Dissertations

A high turbulent intensity combustion chamber has been designed in order to operate with compressible (0.3 < M < 0.5) and preheated (T=500K) air-methane combustion. These conditions will allow the investigation of different flame regimes; most notably the proposed "Thickened Flame" regime. Initial design and flow validation has been completed in order to begin further experimentation. A 10 kHz Time Resolved Particle Image Velocimetry (TR-PIV) system and a 3 kHz Planer Laser Induced Fluorescence (PLIF) system have been integrated with the system in order to diagnose the flow field and the flame respectively. The exhaust and chamber cooling subsystems were designed to comply with safety regulations, and the control systems were set up in a way that allows automated (LabVIEW) and user controlled sequencing. This work's main purpose is to characterize and map the flow properties at maximum flow conditions (M > 0.3) in order to map the following; flow structures, kinetic energy at different length scales, velocity fluctuations and turbulent intensity. PIV measurements are carried out for three different volumetric flow rates (ð???Ì? = 25 scfm, 55 scfm, and 115 scfm) and three different grid geometries for each (BR= 67%, 61%, and 54%). Upon finding that the main flow structure consisted of jets caused by the grid at higher flowrates, experiments were done with a grid BR = 67% which was thinner (50% of original …

Primary Cilia Mechanotransduction And Microtubule Stability In Mechanically Stretched Lung Adenocarcinoma Cells, Monika Rassi Radhika

Theses and Dissertations

The objective of this study is to investigate the role of microtubule based organelle, the primary cilia in lung adenocarcinoma by i) Quantifying the presence of primary cilia in several Non Small Cell Lung Cancer (NSCLC) cell lines in response to mechanical stimuli, ii) Attempting to determine the role of primary cilia in cell migration, iii) Investigating the effects of Paclitaxel(Taxol) resistance in lung cancer cells, iv) Analyzing the response of lung cancer cells to Smoothened Inhibitors and v) Determining the effects of Transforming Growth Factor Beta-1(TGF-β1) induced Epithelial to Mesenchymal Transition(EMT) in lung cancer cells. To ascertain the effects …

Ex Vivo Dna Cloning, Adam B. Fisher

Theses and Dissertations

Genetic engineering of microbes has developed rapidly along with our ability to synthesize DNA de novo. Yet, even with decreasing DNA synthesis costs there remains a need for inexpensive, rapid and reliable methods for assembling synthetic DNA into larger constructs or combinatorial libraries. While technological advances have resulted in powerful techniques for in vitro and in vivo assembly of DNA, each suffers inherent disadvantages. Here, an ex vivo DNA cloning suite using crude cellular lysates derived from E. coli is demonstrated to amplify and assemble DNA containing small sequence homologies. Further, the advantages of an ex vivo approach are …

Computer Hardware: Hardware Components And Internal Pc Connections, Jerome Casey

Instructional Guides

No abstract provided.

Computer Hardware: Building A High Spec Desktop For Gaming, Jerome Casey

Instructional Guides

No abstract provided.

Evaluation Of A Novel Myoelectric Training Device, Joshua A. Arenas

Theses and Dissertations

Recent technological developments have implemented the use of proportional control in prosthetic hands, giving rise to the importance of appropriate myoelectric control. EMG models in the past have assumed a linear proportionality to simplify the EMG-force relationships. However, it has been shown that a non-linear EMG-force relationship may be a more effective model. This study focused on evaluating three different control algorithms for a novel myoelectric training device, consisting of a toy car controlled by EMG signals from the distal muscles in the arm. Sixteen healthy adult subjects (5 male and 11 female) with an average age of 23.6 years …

Project Maelstrom: Forensic Analysis Of The Bittorrent-Powered Browser, Jason Farina, M-Tahar Kechadi, Mark Scanlon

Journal of Digital Forensics, Security and Law

In April 2015, BitTorrent Inc. released their distributed peer-to-peer powered browser, Project Maelstrom, into public beta. The browser facilitates a new alternative website distribution paradigm to the traditional HTTP-based, client-server model. This decentralised web is powered by each of the visitors accessing each Maelstrom hosted website. Each user shares their copy of the website;s source code and multimedia content with new visitors. As a result, a Maelstrom hosted website cannot be taken offline by law enforcement or any other parties. Due to this open distribution model, a number of interesting censorship, security and privacy considerations are raised. This paper explores …

Manipulation Of Gold Nanorod Physicochemical Properties To Enhance Biocompatibility, Uptake And Intracellular Preservation Of Optical Properties For Bio-Imaging And Plasmonic Photo-Therapeutic Applications, Anthony B. Polito

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Gold nanorods (GNRs) due to their tunable optical properties within the near infrared (NIR) region have been identified as strong candidates for new nano-based biomedical applications. Unfortunately, many have reported GNR cytotoxicity and it is still unclear how GNR aspect ratio (AR), surface charge and surface chemistry contribute to cellular association and cytotoxicity. GNR surface chemistry modifications have been reported to reduce cytotoxicity, however they can result in poor cellular uptake and loss of NIR optical properties preventing efficiency with bio-imaging and photo-thermal applications. The aim of this study was to determine if manipulation of GNR physicochemical properties could enhance …

Pwm Buck Converter As A Dynamic Power Supply For Envelope Tracking And Amplitude Modulation, Thomas R. Salvatierra

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Modern energy transmission and signal reproduction techniques rely upon power amplifier (PA) architectures that must operate with high efficiency. Current-source PAs are linear but inherently inefficient; switch-mode PAs are efficient-yet-nonlinear systems, often lacking an efficient means of amplitude modulation (AM) for power transmission. A promising technique for addressing these problems involves replacing the fixed PA supply voltage V_dd with a controlled, variable voltage provided by a dynamic power supply. High-efficiency envelope tracking and amplitude modulation can thereby be provided to both current-source and switch-mode PAs, respectively. This work presents a pulse-width modulated (PWM) dc-dc buck converter for use as the …

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2015, Ven Basco

Libraries' Newsletters

No abstract provided.

Analysis Of The Tapered Transition Waveguide, Ryan J. Shaver

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The tapered transition waveguide is used in waveguide measurement systems for characterizing biaxial electromagnetic properties of materials, but its complex geometry does not support an analytic field solution. To ensure single-mode field behavior, the system includes sections of standard waveguides that only support the dominant mode. As a result, full-wave modeling and simulation of the system is exceedingly large.

Using the finite-element method to analyze the high-order modes at the junctions and to explore field configurations within the transition altering geometry, it is shown that besides the TE10 mode, the TE11 mode is significant. Then, two methods are proposed for …

The Organization Of Kv2.1 Channel Proteins In The Membrane Of Spinal Motoneurons: Regulation By Injury And Cellular Activity, Shannon Hunt Romer

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The intrinsic membrane properties of neurons in the central nervous system are controlled by the tight regulation of membrane-bound ion channels. Rather than existing as static entities operating only in opened or closed states in fixed locations, ion channels are dynamic molecules with the capacity to adopt multiple functional states through conformational changes and/or post-translational modification - enabling flexibility in their activity. Furthermore, the location of ion channels within certain membrane compartments and/or signaling ensembles is critical to synaptic integration and shaping of firing properties, and can also be dynamically modified by changes in neuronal activity and pathology. In mammalian …

Integrated Magnetic Components For Rf Applications, Sheena Hussaini

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Integrated r-f passive components such as inductors, transmission lines, transformers etc, form the basic building blocks in r-f integrated circuits (RFICs) such as matching networks, low noise amplifiers (LNAs), synthesizers and r-f mixers. One main challenge faced by current technology developers in integrating r-f components on integrated chip (IC) are related to operation and size. Tremendous efforts were made for overcoming challenges of r-f integrated circuits to meet growing technology demands.

In general, r-f devices utilize magnetic materials such as ferrites for their operation for improving device performance and scaling. However, due to material properties and size ferrite materials are …

Strain-Induced Energy Band-Gap Opening Of Silicene, Zhonghang Ji

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Inspired by the success of graphene, various two dimensional (2D) structures on different substrates have been proposed. Among others, an allotropic form of silicon, coined "silicene" was shown to exhibit similar properties with graphene of a zero band gap and a Dirac cone shape at the K point in the Brillouin zone. Similar to its counterpart graphene, one of the main obstacles to applying silicene in modern electronics is the lack of an energy band gap. In this work, a systematic study was presented on the structural and electronic properties of single and bi-layered silicon films under various in-plane biaxial …

Virtual Agent Interaction - Improving Cognitive Abilities And Trust For A Complex Visual Search Task, Heather H. Milecki

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Introduction: This thesis research examined a novel decision support aid ("Spatial Cue + Virtual Agent") on human performance in a simulated complex visual search task. Method: Participants in the "Control" condition did not receive support from an aid. Participants in the "Spatial Cue" condition received support from an aid in the form of a bounding box. Participants in the "Spatial Cue + Virtual Agent" condition received support from an aid in the form of a bounding box and a virtual agent. The aids' reliability was held constant at one level, 70 percent. Image difficulty was based on clutter; clutter was …

Design And Performance Analysis Of Magnetic Adder And 16-Bit Mram Using Magnetic Tunnel Junction Transistor, Surya Kiran Akkaladevi

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The scaling down of IC's based on CMOS technology faces significant challenges due to technology advancing factors. The stand-by power becomes comparable to active power due to the increasing leakage current. Power gating and various low-power schemes have been proposed in the past to reduce the stand-by power in CMOS designs. As most random access memory (RAM) used for primary storage in personal computers is volatile memory, which needs constant voltage (power on) to store the data and results in a higher stand-by power. Magnetic Tunnel Junctions (MTJ) transistor has feature of non-volatility, endurance and high density, which makes it …

Theoretical Throughput Capacity: Capabilities Of Human Information Processing During Multitasking, Aerial N. Camden

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Technological advancements in automation have allowed humans to collect data at exorbitant rates. As a result, human multitasking as become an integral part of many government, industrial, and routine activities. However, multitasking can be difficult to study, primarily due to the lack of objective metrics. The Human Operator Informatic Model (HOIM) is an information-theory based model that has been recently developed to combat these difficulties. The HOIM is based on Shannon information theory and can provide an objective, meaningful measure to describe system complexity and overall multitasking performance. The main goal of this work was to validate the HOIM as …

An Improved Adaptive Filtering Approach For Removing Artifact From The Electroencephalogram, Justin Ronald Estepp

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The biophysics of volume conduction that enable electrophysiological data acquisition also result in the mixing of data sources including possible, undesirable noise sources at the electrode interface. This work specifically focuses on improving the performance of the recursive least-squares (RLS) adaptive filtering method for removing eye movement artifact from the electroencephalogram. In biophysically-inspired simulated data, the RLS algorithm is verified to produce results that are inferior to extended infomax independent component analysis (ICA), the most widely used artifact correction approach in this problem space, due to its non-linear filter phase response and the presence of bidirectional contamination, or cross-talk, resultant …

Anterior Cruciate Ligament Biomechanics, Computational Modeling Of Mechanical Behavior And Injury Risk, Bharadwaj Cheruvu

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Knee joint involves interactions from various structures such as cartilage, bone, muscles, ligaments, tendon, as well as neural control. Anterior cruciate ligament (ACL) tears are one of the most frequent soft tissue injuries of the knee. A torn ACL leaves the joint unstable and at risk for further damage to other soft tissues manifested as pain, dislocation, and osteoarthritis. This injury is quite common in sports such as basketball, soccer and football. Females often tear their ACL 2-8 times more frequently than their male counterparts. An ACL injury can be devastating and significantly increases the athlete's risk for osteoarthritis long …

Hierarchical Porous Structures With Aligned Carbon Nanotubes As Efficient Adsorbents And Metal-Catalyst Supports, Hema Vijwani

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The overall goal of this study is two-fold: synthesis of multiscale nanostructures by growing aligned carbon nanotubes on porous foam substrates and investigation of their applicability as adsorbents and catalyst supports for environmental remediation applications. High purity, vertically-aligned arrays of carbon nanotubes (CNT) are grown on open-cell interconnected porous carbon foams by pre-activating them with an oxide buffer layer followed by chemical vapor deposition (CVD). This type of hierarchical morphology provides the capability of increasing surface area by several orders of magnitude, while tuning its morphology for targeted applications. Analytical models are also proposed in this study for specific surface …

Signal Subspace Processing In The Beam Space Of A True Time Delay Beamformer Bank, Nathan Allen Wilkins

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A number of techniques for Radio Frequency (RF) source location for wide bandwidth signals have been described that utilize coherent signal subspace processing, but often suffer from limitations such as the requirement for preliminary source location estimation, the need to apply the technique iteratively, computational expense or others. This dissertation examines a method that performs subspace processing of the data from a bank of true time delay beamformers. The spatial diversity of the beamformer bank alleviates the need for a preliminary estimate while simultaneously reducing the dimensionality of subsequent signal subspace processing resulting in computational efficiency. The pointing direction of …

Hardware Trojan Detection In Cryptography Ip Cores By Library Encoding Method, Dinesh Varma Penumetcha

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Security is the primary issue in current internet world through both software and hardware. The ever increase in demand of consumer electronics requires less design cycle. To speedup design cycle, companies are approaching third parties for common applications IPs like USB, cryptography, DSP etc. These third parties can introduce a malicious content, which is called Trojan. Trojan in the netlist can activate only with special input/trigger. Available Trojan detection techniques like delay, area, power fingerprinting techniques and Automatic Test Pattern Generator (ATPG) method are not suitable as they take more time, less accurate. This thesis presents a hardware Trojan detection …

A Distributed Surrogate Methodology For Inverse Most Probable Point Searches In Reliability Based Design Optimization, James Davidson

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Surrogate models are commonly used in place of prohibitively expensive computational models to drive iterative procedures necessary for engineering design and analysis such as global optimization. Additionally, surrogate modeling has been applied to reliability based design optimization which constrains designs to those which provide a satisfactory reliability against failure considering system parameter uncertainties. Through surrogate modeling the analysis time is significantly reduced when the total number of evaluated samples upon which the final model is built is less than the number which would have otherwise been required using the expensive model directly with the analysis algorithm. Too few samples will …

Mission-Aware Vulnerability Assessment For Cyber-Physical System, Xiaotian Wang

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Designing secure cyber-physical systems (CPS) is fundamentally important. An indispensable step towards this end is to perform vulnerability assessment. This thesis discusses the design and implementation of a mission-aware CPS vulnerability assessment framework. The framework intends to accomplish three objectives including i) mapping CPS mission into infrastructural components, ii) evaluating global impact of each vulnerability, and iii) achieving verifiable results and high flexibility. In order to accomplish these objectives, a model-based analysis strategy is employed. Specifically, a CPS simulator is used to model dynamic behaviors of CPS components under different missions; the framework facilitates a bottom-up approach to traverse a …