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Articles 88531 - 88560 of 197168

Full-Text Articles in Engineering

Graphical User Interface (Gui) Development For An Optical Communication Simulator, Sratsav Ram Shrestha Jan 2017

Graphical User Interface (Gui) Development For An Optical Communication Simulator, Sratsav Ram Shrestha

All Graduate Theses, Dissertations, and Other Capstone Projects

Modeling and simulation tools have been an integral part of engineering world for a long time. Various Electronic Design Automation (EDA) tools have been extensively used in various industries and research to evaluate the performance of electronic systems. The advancement of such design tools also has influenced the optical communication sector such that there has been a continuous progress on the Photonic Design Automation (PDA) tools. Currently, many software for simulating optical communications are available. However, they are very expensive and conceal the information on how components are modeled. To avoid these constraints, we developed our own PDA software for …


Process Parameter Optimization With Numerical Modelling And Experimentation Design Of Binder Jet Additive Manufacturing, Sairam Vangapally Jan 2017

Process Parameter Optimization With Numerical Modelling And Experimentation Design Of Binder Jet Additive Manufacturing, Sairam Vangapally

All Graduate Theses, Dissertations, and Other Capstone Projects

Binder jetting technology is an additive manufacturing technology in which powder materials are binded together layer by layer forming the product from input CAD model. The process involves printing the product layer by layer, curing and sintering. The mechanical properties of 3D printed samples varies based on process parameters, hence there is a need to tune the process parameters for optimal characteristics. Three main parameters namely layer thickness, sintering time and sintering temperature were identified and the study focuses on the effect of parameters on dimensional accuracy and compressive strength of the samples. Full factorial experimental approach was used to …


Nonlinear Control Methods For Single-Ended Primary-Inductor Power Converters, Samet Biricik, Tuan Ngo, Hasan Komurcugil, Malabika Basu Jan 2017

Nonlinear Control Methods For Single-Ended Primary-Inductor Power Converters, Samet Biricik, Tuan Ngo, Hasan Komurcugil, Malabika Basu

Conference papers

This paper investigates nonlinear control methods for single-ended primary-inductor converters (SEPIC). The fastswitching and average models show the converter nonlinearity in terms of inductor currents, capacitor voltages, and the switching duty cycle. The control law intuitively should be nonlinear to drive and guarantee the system stability. Two different control laws based on the passivity and back-stepping technique are examined and designed to have asymptotically global stability in the system. Unlike the passivity method which regulates the duty cycle directly, the back-stepping method adjusts the switching duty by a driver integrator/low pass filter system. The simulation results have shown the benefits …


Design And Modeling Of A Heat Exchanger For Porous Combustor Powered Steam Generators In Automotive Industry, Apratim Dasgupta Jan 2017

Design And Modeling Of A Heat Exchanger For Porous Combustor Powered Steam Generators In Automotive Industry, Apratim Dasgupta

Electronic Theses and Dissertations

A major challenge faced by automobile manufacturers is to achieve reduction of particulate emission to acceptable standards, as the emission standards become more and more stringent. One of the ecologically friendly options to reduce emissions is to develop external combustion in a steam engine as a replacement of the internal combustion engine. There are multiple factors, other than pollution that need to be considered for developing a substitute for Internal Combustion Engine, like specific power, throttle response, torque speed curve, fuel consumption and refueling infrastructure. External combustion in a steam engine seems to be a bright idea, for a cleaner …


Implementation Of Optical Interferometry And Spectral Reflectometry For High Fidelity Thin Film Measurements, Armando Arends-Rodriguez Jan 2017

Implementation Of Optical Interferometry And Spectral Reflectometry For High Fidelity Thin Film Measurements, Armando Arends-Rodriguez

Electronic Theses and Dissertations

An in-house reflectometer/interferometer has been built to investigate the varying curvature and thickness profiles in the contact line region of air, acetone, iso-octane, ethanol, and water on various types of substrates. Light intensity measurements were obtained using our reflectometer/interferomter and then analyzed in MATLAB to produce thickness and curvature profiles. The apparatus is based on the principle of a reflectometer, consisting of different optical elements, probe, light source, and spectrometer. Our reflectometer/interferomter takes measurements in the UV-Vis-IR range (200nm-1000nm). This range is achieved by using a light source that has both a deuterium light (190nm-800nm), a tungsten halogen light (400nm-1100nm), …


On Distributed Estimation For Resource Constrained Wireless Sensor Networks, Alireza Sani Jan 2017

On Distributed Estimation For Resource Constrained Wireless Sensor Networks, Alireza Sani

Electronic Theses and Dissertations

We study Distributed Estimation (DES) problem, where several agents observe a noisy version of an underlying unknown physical phenomena (which is not directly observable), and transmit a compressed version of their observations to a Fusion Center (FC), where collective data is fused to reconstruct the unknown. One of the most important applications of Wireless Sensor Networks (WSNs) is performing DES in a field to estimate an unknown signal source. In a WSN battery powered geographically distributed tiny sensors are tasked with collecting data from the field. Each sensor locally processes its noisy observation (local processing can include compression, dimension reduction, …


Ichetucknee Springs: Measuring The Effects Of Visitors On Water Quality Parameters Through Continuous Monitoring., Sarah Faraji Jan 2017

Ichetucknee Springs: Measuring The Effects Of Visitors On Water Quality Parameters Through Continuous Monitoring., Sarah Faraji

Electronic Theses and Dissertations

Ichetucknee Springs System is in north central Florida, under the jurisdiction of the Suwannee River Water Management District (SRWMD). The Ichetucknee River is one of the most pristine spring-fed rivers in Florida and became a state park in 1970. Over 400,000 people visited the Ichetucknee Springs State Park in 2016. From that total, over 130,000 people came during the tubing season alone (Memorial Day to Labor Day). During the tubing season, only 750 visitors per day are allowed to launch from the North Launch, near the Ichetucknee Head Spring. The park enforces visitor usage of the river during these time …


Mode Evolution In Fiber Based Devices For Optical Communication Systems, Bin Huang Jan 2017

Mode Evolution In Fiber Based Devices For Optical Communication Systems, Bin Huang

Electronic Theses and Dissertations

Space division multiplexing (SDM) is the most promising way of increasing the capacity of a single fiber. To enable the few mode fiber (FMF) or multi-mode fiber (MMF) transmission system, several major challenges have to be overcome. One is the urgent need of ideal mode multiplexer, the second is the perfect amplification for all spatial modes, another one is the modal delay spread (MDS) due to group velocity difference of spatial modes. The main subject of this dissertation is to model, fabricate and characterize the mode multiplexer for FMF transmission. First, we designed a novel resonant mode coupler (structured directional …


Design And Performance Analysis Of Small Scale Horizontal Axis Wind Turbine For Nano Grid Application, Md Mehedi Hasan Jan 2017

Design And Performance Analysis Of Small Scale Horizontal Axis Wind Turbine For Nano Grid Application, Md Mehedi Hasan

College of Graduate Studies: Theses & Dissertations

Wind energy, being easily accessible, environmentally friendly, and being cost effective, has become one of the world’s popular growing renewable energy sources of electricity generation. To spread this technology to mankind it is necessary to develop turbines in this way that people can use it individually and comfortably. This kind of thinking accelerates the advancement of integration of wind turbine with Nano grid concept. Although significant progress has been achieved in the wind technology, there is still scope to reduce the cost and improve the performance of small-scale wind turbines. Moreover, low wind velocity should also need to be utilized …


Measuring Space Radiation Shielding Effectiveness, Amir Bahadori, Edward Semones, Michael Ewert, James Broyan, Steven Walker Jan 2017

Measuring Space Radiation Shielding Effectiveness, Amir Bahadori, Edward Semones, Michael Ewert, James Broyan, Steven Walker

Mathematics & Statistics Faculty Publications

Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat …


Hybrid Metal Oxide Cycle Water Splitting, Richard B. Diver Jr., Robert D. Palumbo, Nathan P. Siegel, James E. Miller Jan 2017

Hybrid Metal Oxide Cycle Water Splitting, Richard B. Diver Jr., Robert D. Palumbo, Nathan P. Siegel, James E. Miller

Other Faculty Research and Publications

Hybrid thermochemical water splitting systems are disclosed that thermally reduces metal oxides particles to displace some but not all of the electrical requirements in a water splitting electrolytic cell. In these hybrid systems, the thermal reduction temperature is significantly reduced compared to two-step metal-oxide thermochemical cycles in which only thermal energy is required to produce hydrogen from water. Also, unlike conventional higher temperature systems where the reduction step must be carried out under reduced oxygen pressure, the reduction step in the proposed hybrid systems can be carried out in air, allowing for thermal input by a solar power tower with …


Computational Fluid Dynamics Proof Of Concept And Analysis Of A Self-Powered Fontan Circulation, Marcus Ni Jan 2017

Computational Fluid Dynamics Proof Of Concept And Analysis Of A Self-Powered Fontan Circulation, Marcus Ni

Electronic Theses and Dissertations

The Fontan circulation is a result of the last (third stage) surgical procedure to correct a single ventricle congenital cardiac disorder in children. Although the Fontan circulation has been successfully established in surgeries over the years, it is flawed and can lead in certain cases to pre-mature death. The main cause of this failure is due to increased pulmonary vascular resistance due to loss pulse pressure and blood flow. In healthy circulations, the heart pumps directly to the lungs, where as "Single Ventricle" patients must use a single sided heart to supply blood to the rest of the body before …


Improved Multi-Task Learning Based On Local Rademacher Analysis, Niloofar Yousefi Jan 2017

Improved Multi-Task Learning Based On Local Rademacher Analysis, Niloofar Yousefi

Electronic Theses and Dissertations

Considering a single prediction task at a time is the most commonly paradigm in machine learning practice. This methodology, however, ignores the potentially relevant information that might be available in other related tasks in the same domain. This becomes even more critical where facing the lack of a sufficient amount of data in a prediction task of an individual subject may lead to deteriorated generalization performance. In such cases, learning multiple related tasks together might offer a better performance by allowing tasks to leverage information from each other. Multi-Task Learning (MTL) is a machine learning framework, which learns multiple related …


Wrong-Way Driving: A Regional Approach To A Regional Problem, Md. Omar Faruk Jan 2017

Wrong-Way Driving: A Regional Approach To A Regional Problem, Md. Omar Faruk

Electronic Theses and Dissertations

Wrong-way driving (WWD) has been problematic on United States highways for decades despite its rare occurrence. Since WWD crashes are rare, recent researchers have studied WWD non-crash events such as WWD 911 calls and WWD citations to understand the overall nature and trend of WWD. This paper demonstrates the regional nature of the WWD problem and proposes regional transportation systems management and operations (Regional TSM&O) solutions to combat this problem. Specifically, it was found that 11% of all WWD multi-data events (e.g., multiple 911 calls for the same WWD event) traveled from one county to another. Additionally, 30% of all …


Polyelectrolyte And Hydrogel Stabilized Liquid Crystal Droplets For The Detection Of Bile Acids, Jinan Deng Jan 2017

Polyelectrolyte And Hydrogel Stabilized Liquid Crystal Droplets For The Detection Of Bile Acids, Jinan Deng

Electronic Theses and Dissertations

Liquid crystal (LC) droplets show great potential as an optical probe for sensor applications due to their large surface areas and stimuli-response director configurations. Bile acids with amphipathic properties, which are formed in liver and secreted into the small intestine, play an important role in the digestion of fats and fat-soluble vitamins. After the digestion process, most of bile acids are recycled back to the liver and ready for the next digestion. Only a few of them are excreted into body fluids. However, there is significant increases in the concentration level of bile acids in body fluids for patients with …


Ellipsometric Measurements Of Alternative Fuels, Leigh Nash Jan 2017

Ellipsometric Measurements Of Alternative Fuels, Leigh Nash

Electronic Theses and Dissertations

Alternative jet fuels will be important in the future to ensure cleaner burning, reliable, and reasonably priced air transportation. One important property that must meet certification standards is the fuel's thermal stability, or its ability to withstand heating before breaking down. Jet fuels are used as engine coolants, and thermally unstable fuels can form deposits in the fuel delivery systems, leading to a loss of fuel flow. In the past, the thermal stability of a fuel was rated using a color standard method. The color of the deposit left on a metal tube that had been heated and exposed to …


A Study Of Copper And Aluminum Incorporated Chromium Oxide Core-Shell Magnetic Nanoparticles, Tamzid Ibn Minhaj Jan 2017

A Study Of Copper And Aluminum Incorporated Chromium Oxide Core-Shell Magnetic Nanoparticles, Tamzid Ibn Minhaj

Graduate Theses/Dissertations

The structural and magnetic properties of copper (Cu) and aluminum (Al) -incorporated chromium oxide (α-Cr2O3, i.e., chromia) inverted core-shell nanoparticles (CSNs) were investigated. The objectives of this study were to determine the role of the substituting (for chromium, Cr) element and of Cu concentration on governing the magnetic properties of the CSNs. For synthesis of the CSNs, α-Cr2O3 nanoparticles were first grown using microwave assisted synthesis whereupon a hydrothermal nanophase epitaxy (HNE) method was used to incorporate Cu or Al in the chromia-based shell of the nanoparticles. The morphology, structure and size characteristics …


Dft Study On The Li Mobility In Li-Ion-Based Solid-State Electrolytes, Shafiqul Islam Jan 2017

Dft Study On The Li Mobility In Li-Ion-Based Solid-State Electrolytes, Shafiqul Islam

Graduate Theses/Dissertations

I have investigated the diffusion mechanisms of Li-ion in amorphous lithium phosphite (LiPO3) with addition of sulphur. By applying the nudge elastic band (NEB) method in crystal LiPO3 and Li3PO4, I confirmed the easing of diffusion pathways for Li ion in LiPO3 which is consistent with the previous theoretical finding[1]. From the diffusion study in 0.5 Li2O- 0.5 P2O5 and 0.4 Li2SO4 – 0.6 (Li2O-P2O5) melts above 3000K performed with ab-initio molecular dynamics (AIMD), produces identical outcome as …


Study Of Nano-Bio Interfaces In Nano-Bio Conjugates: Nanoparticles Of Zinc Oxide (Zno) And Biomolecules Of Glucose, Cytosine, And Thymine, Bithi Paul Jan 2017

Study Of Nano-Bio Interfaces In Nano-Bio Conjugates: Nanoparticles Of Zinc Oxide (Zno) And Biomolecules Of Glucose, Cytosine, And Thymine, Bithi Paul

Graduate Theses/Dissertations

Nano conjugates, composites of inorganic nanomaterials and bio molecules such as DNA, RNA and proteins, establish a sequence of wide varieties of nano-bio boundaries. The formation of these boundaries strongly depends on bio physicochemical reaction of biomolecules coated on the surface of nanomaterials. I am investigating various nano-bio conjugates consisting of zinc oxide (ZnO) nanoparticles with simple biomolecules including glucose and the nitrogenous bases of DNA such as cytosine and thymine. All nano-bio conjugates were fabricated using a standard bio-chemical synthesis process. Structural, physical, bio-chemical interface properties of nano-bio composites were probed using X-ray diffraction (XRD), Raman spectroscopy, and photoluminescence …


Study Of Multiferroic Properties Of Ferroelectric- Ferromagnetic Heterostructures Bzt-Bct/Lsmo, Md Abdullah-Al Mamun Jan 2017

Study Of Multiferroic Properties Of Ferroelectric- Ferromagnetic Heterostructures Bzt-Bct/Lsmo, Md Abdullah-Al Mamun

Graduate Theses/Dissertations

Currently, there has been a flurry of research focused on multiferroic materials due to their potential applications. Lead (Pb)-based ferroelectric and multiferroic materials (PZT, PMN-PT, PZN-PT etc.) have been widely used for sensors, actuators, and electro-mechanical applications due to their excellent dielectric and piezoelectric properties. However, these materials are facing global restriction due to the toxicity of Pb. In this thesis, multiferroic properties of ferroelectric-ferromagnetic heterostructures consist of Pb-free perovskite oxides 0.5Ba(Zr0.2Ti0.8)O3-0.5 (Ba0.7 Ca0.3)TiO3 (BZT-BCT) and La0.7Sr0.3MnO3 (LSMO) have been studied. The heterostructures BZT-BCT/LSMO were …


Comparison Of Ac And Dc Led Light Bulb Efficiency For The Dc House Project, Brandon Stafford Jan 2017

Comparison Of Ac And Dc Led Light Bulb Efficiency For The Dc House Project, Brandon Stafford

Electrical Engineering

This project investigates the efficiency of using LED light bulbs when operated under two different electrical systems: AC and DC systems. The project is in conjunction with the implementation of the DC House system in urban areas. More specifically, this project looks at whether having a hybrid AC and DC system in a typical urban house will increase the efficiency in operating the LED light bulbs, and thus reducing energy consumption and cost. The efficiency of the LED light bulbs are measured by looking at their lumens per watt output. Several light bulbs at four different wattage levels were tested. …


Sun Radio Interferometer Space Experiment (Sunrise): Tracking Particle Acceleration And Transport In The Inner Heliosphere, Farah Alibay, Justin C. Kasper, T. Joseph W. Lazio Jan 2017

Sun Radio Interferometer Space Experiment (Sunrise): Tracking Particle Acceleration And Transport In The Inner Heliosphere, Farah Alibay, Justin C. Kasper, T. Joseph W. Lazio

Space Dynamics Laboratory Publications

The authors present a space-based array designed to localize and track the radio emission associated with coronal mass ejections (CMEs) from the Sun. Radio emission from CMEs is a direct tracer of the particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. These questions are among those highlighted in the Solar Decadal Study, e.g., “Discover and characterize fundamental processes that occur both within the heliosphere and throughout the Universe.” Furthermore, CME radio emission is quite strong such that only a relatively small number of antennas is required, and a small …


Real-Time Optimal Trajectory Planning For Orbital Rendezvous, Satellite Inspection, And Docking Based On Convex Optimization, David K. Geller, Nicholas Ortolano, Aaron Avery Jan 2017

Real-Time Optimal Trajectory Planning For Orbital Rendezvous, Satellite Inspection, And Docking Based On Convex Optimization, David K. Geller, Nicholas Ortolano, Aaron Avery

Space Dynamics Laboratory Publications

Convex optimization techniques have deterministic convergence properties, are self-starting, i.e., they do not require an initial guess, and have been tested in real-time environments. These optimization techniques are applied to the trajectory planning problem for orbital rendezvous and proximity operations. Spacecraft rendezvous, inspection, and final approach trajectories are considered. Optional trajectory constraints are considered including approach corridors, keep-out zones, and maximum thrust acceleration levels. Two linear dynamics models are investigated: Clohessy-Wiltshire dynamics to describe the relative motion in an LVLH frame, and a new relative orbital motion dynamics model to describe the motion relative to a spinning or uncontrolled spacecraft. …


Nsgt: Software-Defined Nanosatellite Ground Transceiver, Space Dynamics Laboratory Jan 2017

Nsgt: Software-Defined Nanosatellite Ground Transceiver, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Ground station operators need an affordable, configurable solution to communicate with small satellite radios.

SDL’s software-defined nanosatellite ground transceiver is low cost and highly configurable. It is compatible with a broad range of industry radios, including SDL’s Cadet U and Cadet PLUS.

The nanosatellite ground transceiver can also be used for benchtop testing during spacecraft integration.


Calibration & Testing, Space Dynamics Laboratory Jan 2017

Calibration & Testing, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

WHY CALIBRATE?

Once you have designed and built a sensor, it is essential that you calibrate it—especially when it comes to space instruments. Calibration is the only way to translate your raw sensor data into scientific units that can be analyzed for vital information. Science can only occur when you have calibrated data.

In addition, calibration helps you verify that your sensor meets the requirements and helps to identify performance issues under operational conditions before you fly. Thorough calibration testing before deployment significantly increases the probability of mission success.


Lifelong Learning: A Strategic Analysis Of Education, Iwasan D. Kejawa Ed.D Jan 2017

Lifelong Learning: A Strategic Analysis Of Education, Iwasan D. Kejawa Ed.D

Department of Teaching, Learning, and Teacher Education: Faculty Publications

Are outdated traditional education, distance education, information technological infrastructure, partnerships and financial resources common problematic issues facing many of the educational institutions in our world today? With this into considerations, are these issues vital in order to stabilize the political and economic embroidery of an institution or organization, and its psychological and sociological awareness? What is it that is to be learned and thought in our institutions and, what really is lifelong education; and how is to be carried out in the society of ours? It is found that education may be the training of the mind to perform desire …


Reliable Spectrum Hole Detection In Spectrum-Heterogeneous Mobile Cognitive Radio Networks Via Sequential Bayesian Non-Parametric Clustering, Alireza Zaeemzadeh Jan 2017

Reliable Spectrum Hole Detection In Spectrum-Heterogeneous Mobile Cognitive Radio Networks Via Sequential Bayesian Non-Parametric Clustering, Alireza Zaeemzadeh

Electronic Theses and Dissertations

In this work, the problem of detecting radio spectrum opportunities in spectrum-heterogeneous cognitive radio networks is addressed. Spectrum opportunities are the frequency channels that are underutilized by the primary licensed users. Thus, by enabling the unlicensed users to detect and utilize them, we can improve the efficiency, reliability, and the flexibility of the radio spectrum usage. The main objective of this work is to discover the spectrum opportunities in time, space, and frequency domains, by proposing a low-cost and practical framework. Spectrum-heterogeneous networks are the networks in which different sensors experience different spectrum opportunities. Thus, the sensing data from sensors …


Analysis Of Pedestrian Crash Characteristics And Contributing Causes In Central Florida, Zainb Bianco Jan 2017

Analysis Of Pedestrian Crash Characteristics And Contributing Causes In Central Florida, Zainb Bianco

Electronic Theses and Dissertations

This research investigates the main reasons leading the State of Florida to be ranked among the worst states in terms of pedestrian safety with four metro areas considered the most dangerous for pedestrians among all the United States as reported in the Dangerous by Design report. The study analyzes the characteristics and contributing causes of pedestrian crashes that occurred in Central Florida over a 5 year-period (2011-2015) at intersections and along roadway segments at mid-block locations using the data obtained from the Signal 4 Analytics database. All pedestrian related crashes were compiled and all the 6,789 crash reports were studied …


Wearable Passive Wireless Mems Respiration Sensor, Sina Moradian Jan 2017

Wearable Passive Wireless Mems Respiration Sensor, Sina Moradian

Electronic Theses and Dissertations

In this study a passive sensor that wirelessly monitors the profile of the human respiratory system is presented. The sensor was designed to be wearable, weighs less than 10 grams and is durable. The sensor is made of a RF piezoelectric MEMS resonator and an ultra-high frequency antenna made of a thin metal film formed on a flexible substrate . The resonance frequency of the TPoS resonator shifts as a function of condensation and evaporation of water vapor on the surface of the resonator and changes in resonator's temperature. These parameters change in each in response to inspiration and expiration …


Characteristics Of Hydrogel-Wetted Thin Films, James Owens Jan 2017

Characteristics Of Hydrogel-Wetted Thin Films, James Owens

Electronic Theses and Dissertations

The meniscus region of a thin film is known to have high heat transfer properties due to high evaporation rates and activation of latent heat. The region known as the thin film meniscus (δfilm lt& 2 µm ) can account for more than half of the total heat transfer of a droplet or film. This study focuses on the potential elongation and curvature amplification of the thin film meniscus region by the implementation of a layer of high hydrogen bonding (hydrogel) film on which the liquid meniscus is built. Forced wetting via liquid propagation though this hydrogel layer in the …