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Articles 62821 - 62850 of 198160

Full-Text Articles in Engineering

Energy-Efficient Signal Conversion And In-Memory Computing Using Emerging Spin-Based Devices, Soheil Salehi Mobarakeh Jan 2020

Energy-Efficient Signal Conversion And In-Memory Computing Using Emerging Spin-Based Devices, Soheil Salehi Mobarakeh

Electronic Theses and Dissertations, 2020-2023

New approaches are sought to maximize the signal sensing and reconstruction performance of Internet-of-Things (IoT) devices while reducing their dynamic and leakage energy consumption. Recently, Compressive Sensing (CS) has been proposed as a technique aimed at reducing the number of samples taken per frame to decrease energy, storage, and data transmission overheads. CS can be used to sample spectrally-sparse wide-band signals close to the information rate rather than the Nyquist rate, which can alleviate the high cost of hardware performing sampling in low-duty IoT applications. In my dissertation, I am focusing mainly on the adaptive signal acquisition and conversion circuits …


Wind Turbine Generator Overheating Solution, Gopal Singh Jan 2020

Wind Turbine Generator Overheating Solution, Gopal Singh

Electronic Theses and Dissertations, 2020-2023

An increase in the demand for electrical power and tremendous growth of renewable energy sources has been seen in the last decade, which resulted in designing the wind turbine system components for higher load point performance, resulting in higher annual energy production. Cost optimization, weight reduction, and lower non-conformance cost are some of the expectations that the wind turbine needs to meet in the present stringent market condition. Overheating of the wind turbine system components is one of the primary challenges to overcome when the system operates at a higher load point. The overheating issue of the wind turbine generator …


Characterization Of Left Ventricular Volumes And Ejection Fraction In Patients With A Left Ventricular Assist Device, Viswajith Siruvallur Vasudevan Jan 2020

Characterization Of Left Ventricular Volumes And Ejection Fraction In Patients With A Left Ventricular Assist Device, Viswajith Siruvallur Vasudevan

Electronic Theses and Dissertations, 2020-2023

In the treatment of heart patients, as a bridge to recovery, the challenge currently in using a continuous-flow left ventricular assist device (LVAD), is to provide a method to monitor the recovery of the heart. This dissertation addresses the hypothesis that continuous monitoring of the ejection fraction of a patient implanted with an LVAD should be to examine the progress of the patient without the need for excessive in vivo measurements. Also, the ejection fraction can be used to provide a control mechanism for the pump depending on the requirements of each patient. In this dissertation, the left ventricle, in …


Increasing Accuracy Performance Through Optimal Feature Extraction Algorithms, Genevieve Sapijaszko Jan 2020

Increasing Accuracy Performance Through Optimal Feature Extraction Algorithms, Genevieve Sapijaszko

Electronic Theses and Dissertations, 2020-2023

This research developed models and techniques to improve the three key modules of popular recognition systems: preprocessing, feature extraction, and classification. Improvements were made in four key areas: processing speed, algorithm complexity, storage space, and accuracy. The focus was on the application areas of the face, traffic sign, and speaker recognition. In the preprocessing module of facial and traffic sign recognition, improvements were made through the utilization of grayscaling and anisotropic diffusion. In the feature extraction module, improvements were made in two different ways; first, through the use of mixed transforms and second through a convolutional neural network (CNN) that …


Mfpa: Mixed-Signal Field Programmable Array For Energy-Aware Compressive Signal Processing, Adrian Tatulian Jan 2020

Mfpa: Mixed-Signal Field Programmable Array For Energy-Aware Compressive Signal Processing, Adrian Tatulian

Electronic Theses and Dissertations, 2020-2023

Compressive Sensing (CS) is a signal processing technique which reduces the number of samples taken per frame to decrease energy, storage, and data transmission overheads, as well as reducing time taken for data acquisition in time-critical applications. The tradeoff in such an approach is increased complexity of signal reconstruction. While several algorithms have been developed for CS signal reconstruction, hardware implementation of these algorithms is still an area of active research. Prior work has sought to utilize parallelism available in reconstruction algorithms to minimize hardware overheads; however, such approaches are limited by the underlying limitations in CMOS technology. Herein, the …


A Corridor Level Gis-Based Decision Support Model To Evaluate Truck Diversion Strategies, Samar Younes Jan 2020

A Corridor Level Gis-Based Decision Support Model To Evaluate Truck Diversion Strategies, Samar Younes

Electronic Theses and Dissertations, 2020-2023

Increased urbanization, population growth, and economic development within the U.S. have led to an increased demand for freight travel to meet the needs of individuals and businesses. Consequently, freight transportation has grown significantly over time and has expanded beyond the capacity of infrastructure, which has caused new challenges in many regions. To maintain quality of life and enhance public safety, more effort must be dedicated to investigating and planning in the area of traffic management and to assessing the impact of trucks on highway systems. Traffic diversion is an effective strategy to reduce the impact of incident-induced congestion, but alternative …


Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes, Salimeh Tofighi Jan 2020

Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes, Salimeh Tofighi

Electronic Theses and Dissertations, 2020-2023

This dissertation explores two main topics: Transient nonlinear refraction of air in Mid-IR spectral range and nonlinear optical properties of organometallic complexes. For seeing a vibrational and rotational Raman response the molecule should be Raman active. The first requirement for being a Raman active molecule is that the polarizability of molecule must be anisotropic. Linear symmetric molecules do have rotational Raman spectra. Not all the vibrational mode can be excited by a femtosecond pulse. The pulsewidth of our excitation beam should be less than the half of the vibration period. In this dissertation my excitation pulsewidth is not short enough …


Heat Transfer And Correlations Of Jet Array Impingement With Flat And Pimple-Dimpled Plate, Husam Nizar Ahmad Zawati Jan 2020

Heat Transfer And Correlations Of Jet Array Impingement With Flat And Pimple-Dimpled Plate, Husam Nizar Ahmad Zawati

Electronic Theses and Dissertations, 2020-2023

This study compares and analyses the heat transfer between a novel jet array impingement configuration (designated as NPR) and a baseline jet orifice plate (flat) in a maximum crossflow scheme. Both jet plates feature inline arrays of 20 x 26 circular air jets that orthogonally impinge on a flat target surface consisting of 20 segments, parallel to the jet plates. The NPR plate consists of staggered semi-spherical pimples (protrusions) and dimples (imprints) with a jet-to-pimple diameter ratio (Dj,p/Dp) of 0.07 and jet length-to-pimple diameter ratio (L/Dj,p) of ~ 1 with a protrusion ratio (tp/Dj,p) of 2.78. The dimples (imprints) have …


Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas Jan 2020

Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas

Electronic Theses and Dissertations, 2020-2023

The decision on whether to use a mid wave infrared (MWIR) or long wave infrared (LWIR) sensor for a given task can be a formidable verdict. The scope entails facts about the observable source, the atmospheric interactions, and the sensor parameters within the hardware device. Even when all the individual metrics are known, the combination ultimately determines whether a MWIR or LWIR sensor is more appropriate. Despite the vast number of variables at play, the reduction of inputs through focused studies can provide essential insight into MWIR and LWIR comparisons. This dissertation focuses on the roles of point source target …


An Information-Potential Approach To Airborne Lidar Point Cloud Sampling And Assessment, Kristian Damkjer Jan 2020

An Information-Potential Approach To Airborne Lidar Point Cloud Sampling And Assessment, Kristian Damkjer

Electronic Theses and Dissertations, 2020-2023

In the last decade, airborne laser scanning (ALS) systems have evolved to provide increasingly high-fidelity topographic mapping data. Point clouds and derivative models now rival photogrammetrically-derived equivalents. Yet, despite technological advancement and widespread adoption of light detection and ranging (LiDAR) data, sampling guidance and data quality (DQ) assessment remains an open area of research due to the volumetric and irregularly sampled nature of point clouds and the persistent influence of assumptions from early point scanning LiDAR systems on assessment methods. This dissertation makes several contributions to the research area by considering point cloud sampling strategies and DQ assessment from an …


Modeling Flow And Nitrate Transport In Karst Groundwater Basins, Yuan Gao Jan 2020

Modeling Flow And Nitrate Transport In Karst Groundwater Basins, Yuan Gao

Electronic Theses and Dissertations, 2020-2023

Understanding the groundwater flow in karst aquifers and the effect of best management practices (BMPs) on nitrate decrease in spring discharge is critical for effective management and protection of karst water resources. However, the control on the conduit network's impacts on spring discharge and nitrate concentration is not fully understood, and the cumulative effects of BMP on reducing nitrate in karst groundwater systems have not been evaluated at the basin scale. In this dissertation, a coupled Conduit Flow Process (CFPv2) and Conduit Mass Three-Dimensional (CMT3D) model was applied to evaluate the biosorption-activated media (BAM)-based BMP on nitrate removal in Silver …


Viscoelastic Analysis Of High Strain Composites For Deployable Structures In Space Applications, Andrew Gomez-Delrio Jan 2020

Viscoelastic Analysis Of High Strain Composites For Deployable Structures In Space Applications, Andrew Gomez-Delrio

Electronic Theses and Dissertations, 2020-2023

Thin-ply composite laminates capable of enduring high strains are currently under investigation for compliant deployable spacecraft structures. Deployable structures such as booms fabricated from these materials can be flattened and coiled to high curvatures, achieving a compact configuration for stowage. Once in orbit, they are released with minimal actuation for deployment, allowing the operational geometry to be recovered. Previous studies have shown that the viscoelastic properties of the composite epoxy matrix can negatively impact final shape accuracy due to stress relaxation during stowage. In addition, since the strain energy stored is relied upon for deployment, considerable relaxation can potentially result …


Rotational And Shower Head Cooling Hole Effects On Leading-Edge Jet Impingement Heat Transfer, Weston Olson Jan 2020

Rotational And Shower Head Cooling Hole Effects On Leading-Edge Jet Impingement Heat Transfer, Weston Olson

Electronic Theses and Dissertations, 2020-2023

Jet Impingement and shower head cooling are critical cooling techniques used to maintain turbine blades at operational temperatures. Jet impingement is extremely effective at removing large amounts of heat flux from the target surface, the inner blade wall, through stagnation point heat transfer. Shower head cooling produces a cooling film around the exterior of the blade, in return reducing external heat flux. The current work consisted of investigating the jet impingement effectiveness with rotational effects for two different cooling schemes. The analysis was conducted numerically using STAR CCM+ with two different turbulence models, the three equation Lag Elliptic Blending K …


Removal Of Heavy Metals From Landfill Leachate Using Electrospun Polyelectrolyte Complex Fiber-Laminated Ultrafiltration Membrane, Amirsalar Rabbani Esfahani Jan 2020

Removal Of Heavy Metals From Landfill Leachate Using Electrospun Polyelectrolyte Complex Fiber-Laminated Ultrafiltration Membrane, Amirsalar Rabbani Esfahani

Electronic Theses and Dissertations, 2020-2023

Ultrafiltration (UF) is a low-pressure membrane process that yields higher permeate flux and saves significant operating costs compared to NF/RO. However, UF has not been applied as a primary method for landfill leachate treatment due to its large pore size. This research investigated the removal of heavy metals from landfill leachate using an UF membrane laminated with fiber mats produced from electrospinning of a polyelectrolyte complex. In this research, we modified the surface of the UF membrane with two polyelectrolytes including Polyacrylic Acid (PAA) and Polyallylamine Hydrochloride (PAH). The removal of heavy metals including Pb, Cd, and Cu from water …


Conception D’Oreilles Artificielles Réalistes Dédiées À L’Étude Du Confort Acoustique Et Physique Des Protecteurs Auditifs Intra-Auriculaires, Simon Benacchio, Olivier Doutres, Éric Wagnac, Franck Sgard Jan 2020

Conception D’Oreilles Artificielles Réalistes Dédiées À L’Étude Du Confort Acoustique Et Physique Des Protecteurs Auditifs Intra-Auriculaires, Simon Benacchio, Olivier Doutres, Éric Wagnac, Franck Sgard

Rapports de recherche scientifique

Au Québec, environ 360 000 travailleurs sont exposés quotidiennement à des niveaux de bruit susceptibles d’engendrer des problèmes d’audition. Les protecteurs auditifs individuels sont souvent utilisés pour pallier ce problème. Cependant, l’inconfort lié à l'utilisation de ces protecteurs limite la durée du port et donc l'efficacité de la protection. Le développement d'outils de conception acoustique minimisant les sources d’inconforts auditifs et physiques de ces protecteurs tout en assurant une atténuation adéquate constitue le contexte de cette recherche.

La présente étude se concentre sur deux indicateurs du confort associés au port des bouchons d’oreille : l’atténuation et l’effet d’occlusion. L’atténuation quantifie …


Production Allocation Of Reservoir Layers Using Data-Driven Reservoir Modeling, Semaa Alessa Jan 2020

Production Allocation Of Reservoir Layers Using Data-Driven Reservoir Modeling, Semaa Alessa

Graduate Theses, Dissertations, and Problem Reports (ETD)

The pros of having a commingled layer scheme would be considered high with successful reservoir management. If not, the cons will impact the production drastically as unfortunate consequences may result in reservoir fluids communication, well integrity issues, and production termination. Although the plane requires optimizing production with minimal capital investments and operating expenses, it is an enormous challenge considering commingled layers frequent surveillance and workover requirements.

As the value of information is a decision tool for the surveillance frequency, the oil industry often uses static assumptions as an economical replacement of dynamic measurements such as KH static modeling. However, the …


Confirmation Of Tdm Capabilities In Modeling Compartmentalized Wag Eor, Anthony William Morrow Jan 2020

Confirmation Of Tdm Capabilities In Modeling Compartmentalized Wag Eor, Anthony William Morrow

Graduate Theses, Dissertations, and Problem Reports (ETD)

Data-Driven Reservoir Modeling (DDRM), commonly referred to as Top-Down Modeling (TDM), is a relatively new and cutting-edge approach to the traditional numerical reservoir modeling and simulation techniques. DDRM uses artificial intelligence and machine learning in tandem to construct full-field models using measured data instead of calculations that refer to equations derived from averaged values and type curves. TDM allows all of the measured data from a field to be combined and used towards generating predictions of the production on a well by well basis for a specific field. Due to TDM not using the traditional physics-based approach, it is subjected …


Pulsed Power Control System, Logan Curtis Jan 2020

Pulsed Power Control System, Logan Curtis

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Using Batman Software To Analyze Metabolic Changes In Type 1 Diabetes-Susceptible Rats, Connor Hall Jan 2020

Using Batman Software To Analyze Metabolic Changes In Type 1 Diabetes-Susceptible Rats, Connor Hall

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Additive Manufacturing In Space, Japheth Hayman Jan 2020

Additive Manufacturing In Space, Japheth Hayman

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Three-Dimensional Measurement Of Electron Temperature And Density In A Split Ring Resonator Microplasma, Neil Laya Jan 2020

Three-Dimensional Measurement Of Electron Temperature And Density In A Split Ring Resonator Microplasma, Neil Laya

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Reactions At The Critical Point Of Solution, Jason Mote Jan 2020

Reactions At The Critical Point Of Solution, Jason Mote

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Directed Assembly Of Binary Magnetic Particles, Thomas Thelen Jan 2020

Directed Assembly Of Binary Magnetic Particles, Thomas Thelen

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Tunable Refractive Index Through Spatially Modified Nanoparticle Films For Long-Range Spr Biosensing Applications, Stephen Joshua Binderup Jan 2020

Tunable Refractive Index Through Spatially Modified Nanoparticle Films For Long-Range Spr Biosensing Applications, Stephen Joshua Binderup

Graduate Research Theses & Dissertations

Despite optics and refraction being among the oldest scientific principles, material limitations have prevented scientists from taking full advantage of the potential this technology holds. Indeed, films with designer optical properties have potential for use in exotic cloaking architectures, advanced waveguides, and precise optical biosensors. This thesis focuses on the fabrication methodology for making thin films with refractive index tuned to a desired value through self-assembly of amorphous nanoparticle films made of organosilicate materials. The inclusion of a slowly evaporating polymer phase along with the organosilicate nanoparticles results in nanopores formed within the film, which effectively reduce the film’s refractive …


Overview Of Changes To The S-Stem And Iuse Programs, Stephanie E. August Jan 2020

Overview Of Changes To The S-Stem And Iuse Programs, Stephanie E. August

Computer Science Faculty Works

The National Science Foundation (NSF) Division of Undergraduate Education (DUE) Scholarships in Science, Technology, Engineering, and Mathematics (S-STEM, NSF 20-526) [5] and Improving Undergraduate STEM Education: Education and Human Resources (IUSE: EHR, NSF 19-601) [4] programs are frequent funding targets for the computer science education (CSEd) community. These programs were discussed in the context of evaluation in an earlier column [1]. NSF programs evolve over time to respond to community needs and changes at the Foundation. The purpose of this column is to bring recent changes to S-STEM and IUSE and other changes at NSF that impact CSEd to the …


Levitate, Stephen Hargreaves, Isaac Hammonds, Russel Pease, Joseph Morris Jan 2020

Levitate, Stephen Hargreaves, Isaac Hammonds, Russel Pease, Joseph Morris

Williams Honors College, Honors Research Projects

Levitate is designed to create a healthier work environment by providing a way of entertaining a worker while not distracting them. To fulfill this task, the device needs to be interesting and self-sufficient while not being overly flashy. To complete this task, Levitate is designed so that it is able to lift a platform from rest using magnetism and that will be able to stabilize itself using electromagnets. It initiates this process by lifting the permanent magnet using servo motors. Then, the device is able to achieve stability through the use of hall sensors feeding their results to the board …


Solar-Powered Exploration Of The Venus Atmosphere, Marc Migliozzi, Cory Everman, Rebecca Buerhle, Umar Muhammed, Steven Abbate, Chase Champagne Jan 2020

Solar-Powered Exploration Of The Venus Atmosphere, Marc Migliozzi, Cory Everman, Rebecca Buerhle, Umar Muhammed, Steven Abbate, Chase Champagne

Williams Honors College, Honors Research Projects

The objective of this study was to design a solar powered, unmanned aircraft to orbit in the upper Venus atmosphere and search for signs of alien life. Topics of flight conditions, signs of life, basic mission plan, source of power, design process, instrumentation, and final designs are covered. Solar energy is ideal for this type of mission because it is the only reliable and abundant energy source accessible for long term space travel. The target altitude, being 60 to 70 km, has winds of up to 95 m/s. The aircraft will need to remain stable under such conditions. Due to …


Controlled Crystallization Of Pet Filaments In Additive Manufacturing, Ryan Kordahi Jan 2020

Controlled Crystallization Of Pet Filaments In Additive Manufacturing, Ryan Kordahi

Williams Honors College, Honors Research Projects

Polyethylene terephthalate (PET) appears in daily life in many forms, the most common being disposable soft drink bottling. To deal with the ever-growing quantitity of disposed PET (both in landfills and environment), a waste plan revolving around depolymerization should be implemented. Specifically, the potential of PET depolymerization through aminolysis into useful, low molecular weight monomers will be explored with the end goal of producing a 3D printing filament and analyzing economic feasibility.


Optimization Of E-Textiles For Lactic Acid Detection, Andrew Laboy, Mallory David Jan 2020

Optimization Of E-Textiles For Lactic Acid Detection, Andrew Laboy, Mallory David

Williams Honors College, Honors Research Projects

The overall goal of the project is to develop an e-textile that will be able to determine different characteristics of an athlete's health through multiple sensors. The goal of these sensors is to monitor physiological parameters for health and fitness uses in real time. Building from the existing sodium concentration sensor, these new sensors will detect lactate levels within sweat to monitor instantaneous health which allows customization of workout and overall health regimen.


Evaluating Rubber Aging On Tire Durability: Quantitative Evaluation Of Rubber Aging, Brian Auffenberg Jan 2020

Evaluating Rubber Aging On Tire Durability: Quantitative Evaluation Of Rubber Aging, Brian Auffenberg

Williams Honors College, Honors Research Projects

Rubber is considered one of the most important polymers in the world due to its variety of uses. There are many different conditions that can affect the useful life of rubber. The purpose of this research was to determine how the mechanical loading on the rubber may affect the aging of the rubber. The scope of the project was to focus on the rubber used for tire production. The research was limited to focusing only on rubber supplied by industry mentors which was styrene-butadiene rubber. By varying the length of time for testing as well as the temperature of the …