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Articles 40921 - 40950 of 196010

Full-Text Articles in Engineering

Monte Carlo Particle Simulation Of Avalanche Breakdown In A Reverse Biased Diode With Full Band Structure, Zeyi Sun, Manish Kizhakkeveettil Mathew, Ryan From, Donghyun Kim Jan 2022

Monte Carlo Particle Simulation Of Avalanche Breakdown In A Reverse Biased Diode With Full Band Structure, Zeyi Sun, Manish Kizhakkeveettil Mathew, Ryan From, Donghyun Kim

Engineering Management and Systems Engineering Faculty Research & Creative Works

To model the avalanche breakdown of a voltage regulator diode under reverse bias, a computationally rigorous device physics model using the Monte Carlo method to solve charge carrier Boltzmann transport equations (BTEs) is proposed. The transport of energetic charge carriers is calculated by using the full energy band instead of the non-parabolic band structure. The position-dependent doping profile found in real diodes is modeled accurately and time-efficiently. A two-step method is introduced to accelerate the simulation of avalanche breakdown. With the proposed model, the expected IV characteristics of a voltage regulator diode under reverse bias are simulated. The transport of …

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The Effects Of Mixing Multi-Component Hlw Glasses On Spinel Crystal Size, C. (Charmayne) E. Lonergan, J. Rice, C. Skidmore, M. J. Schweiger, P. Hrma Jan 2022

The Effects Of Mixing Multi-Component Hlw Glasses On Spinel Crystal Size, C. (Charmayne) E. Lonergan, J. Rice, C. Skidmore, M. J. Schweiger, P. Hrma

Materials Science and Engineering Faculty Research & Creative Works

The Hanford Waste Treatment and Immobilization Plant will vitrify radioactive waste into borosilicate glass. The high-level waste (HLW) glass formulations are constrained by processing and property requirements, including restrictions aimed at avoiding detrimental impacts of spinel crystallization in the melter. To understand the impact of glass chemistry on crystallization, two HLW glasses precipitating small (∼5 μm) spinel crystals were individually mixed and melted with a glass that precipitated large (∼45 μm) spinel crystals in ratios of 25, 50, and 75 wt.%. The size of spinel crystals in the mixed glasses varied from 5 to 20 μm. Small crystal size was …

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The Role Of Microstructure On High-Temperature Oxidation Behavior Of Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke Jan 2022

The Role Of Microstructure On High-Temperature Oxidation Behavior Of Hafnium Carbide, Jonathan A. Scott, Xiaoqing He, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Microstructure development of the products formed upon oxidation of hafnium carbide (HfCx, x = 0.65, 0.81, or 0.94) at 1300°C and 0.8 mbar oxygen pressure was investigated using Raman spectroscopy, X-ray diffraction, electron microscopy, and electron energy-loss spectroscopy. For all specimens a multilayered oxide scale was observed featuring an outermost porous hafnia layer and an interlayer adjacent to the parent carbide containing hafnia interspersed with carbon. The outermost hafnia features coarse pores presumably formed during initial stages of oxidation to allow rapidly evolving gaseous products to escape from the oxidation front. As the oxidation scale thickens, diffusional resistance results in …

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Fundamental Effects Of Al And Ta On Microstructure And Phase Transformations In The Al–Cr–Mo–Ta–Ti Refractory Complex Concentrated Alloy System, Austin E. Mann, Joseph William Newkirk Jan 2022

Fundamental Effects Of Al And Ta On Microstructure And Phase Transformations In The Al–Cr–Mo–Ta–Ti Refractory Complex Concentrated Alloy System, Austin E. Mann, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The effect of aluminum and tantalum concentrations on a refractory metal complex concentrated alloy is reported, particularly with respect to their effect on microstructure and phase composition of the alloy in cast and annealed form. Alloys with an equiatomic composition, (AlCrMoTaTi), an aluminum-lean composition (Al0.75CrMoTaTi), and a tantalum-lean composition (AlCrMoTa0.75Ti) are produced via arc melting. The alloys exhibit multiphase structures, confirmed by X-ray diffraction, microstructural characterization, and thermal analysis. The minor off-equiatomic adjustments of aluminum and tantalum in this alloy system did not drastically alter the prevalence of the Cr–Ta-based Laves phase. Correlations between thermodynamic predictions and observed phase transformations …

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Effect Of Spallation On Oxidation Kinetics Of Heat-Resistant Cr–Ni Austenitic Steels On Air And Combustion Atmosphere, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlewski, Wenhui Zhu Jan 2022

Effect Of Spallation On Oxidation Kinetics Of Heat-Resistant Cr–Ni Austenitic Steels On Air And Combustion Atmosphere, Simon N. Lekakh, Oleg Neroslavsky, Mei Li, Larry Godlewski, Wenhui Zhu

Materials Science and Engineering Faculty Research & Creative Works

Thin-walled castings made from Cr–Ni austenitic steels offer a combination of light weight of a near-net component with significant high temperature corrosion protection by forming a surface oxide layer. However, above critical service conditions (temperature, atmosphere, thermal cycling), oxidized surface can result in intensive surface degradation due to scale spallation. Scale spallation can decrease the wall thickness which could be detrimental to the in-service life of thin-walled castings. Experiments and stochastic simulations of spallation assisted oxidation were performed with three cast austenitic heat-resistant steels having different Cr–Ni concentrations at temperatures between 900 and 1000 ℃ on air and water vapor …

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On The Effect Of Hot Rolling On Inclusion Size And Distribution In A Cast Aisi 1070 Steel Railroad Wheel, Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, Mario F. Buchely, Richard Pilon Jan 2022

On The Effect Of Hot Rolling On Inclusion Size And Distribution In A Cast Aisi 1070 Steel Railroad Wheel, Jacob M. Summers, Soumava Chakraborty, Laura Bartlett, Ronald J. O'Malley, Mario F. Buchely, Richard Pilon

Materials Science and Engineering Faculty Research & Creative Works

The goal of this work is to examine the effect of hot deformation on shrinkage porosity and nonmetallic inclusions in an AISI 1070 grade steel industrially produced wheel casting. Steel cleanliness is an important consideration as it influences the mechanical properties of the final product. A high density of porosity and inclusions have been shown to be detrimental for mechanical properties, especially during hot rolling. Using a laboratory-scale rolling mill, cast preforms were subjected to a 66% cumulative reduction to determine the effect of thermomechanical processing on void closure and inclusions that may produce anisotropy in mechanical properties. Quantitative automated …

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Cal Poly Construction Management Summer Bootcamp 2022, Mason A. Heinse Jan 2022

Cal Poly Construction Management Summer Bootcamp 2022, Mason A. Heinse

Construction Management

The purpose of this paper is to outline the intent and key objectives of the Cal Poly Construction Management Summer Bootcamp. This project was developed through collaboration with Cal Poly Construction Management faculty and other contributors to create a multi-scope project with the objective of creating a summer bootcamp. The camp was proposed to assist the San Luis Obispo County Office of Education and the Central Coast Homebuilders Association with promoting skilled trades education in high schools. Local high schools currently implement the Building Industry Technology Academy (BITA) curriculum, which has proven difficult for students to enroll in or complete. …

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Impact Of Covid-19 On Aviation-Wildlife Strikes Across Europe, Isabel C. Metz, Marta Giordano, Dionysios Ntampakis, Marianna Moira, Anneke Hamann, Rosanne Blijleven, Jürgen J. Ebert, Alessandro Montemaggiori Jan 2022

Impact Of Covid-19 On Aviation-Wildlife Strikes Across Europe, Isabel C. Metz, Marta Giordano, Dionysios Ntampakis, Marianna Moira, Anneke Hamann, Rosanne Blijleven, Jürgen J. Ebert, Alessandro Montemaggiori

Human–Wildlife Interactions

Collisions between aircraft and wildlife (i.e., wildlife strikes) pose a serious threat toward the safety of aircraft, its crew, and passengers. The effects of COVID-19 related travel restrictions on wildlife strikes are unknown. With this study, we aim to address this information gap by assessing the changes of wildlife hazard management performance across European airports during the lockdown period (e.g., period of reduced operations and borders closure in spring 2020). We also sought to raise awareness of the importance of wildlife strike prevention in times of reduced operations. The objective of our study was to compare wildlife strike data before …

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An Awe-Enhanced Wideband Subdomain Dg-Rtc Algorithm In Solving Electromagnetic Problems, Shimin Liu, Li (Lijun) Jun Jiang, Ping Li Jan 2022

An Awe-Enhanced Wideband Subdomain Dg-Rtc Algorithm In Solving Electromagnetic Problems, Shimin Liu, Li (Lijun) Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this research, a Robin transmission condition enriched frequency-domain discontinuous Galerkin (DG-RTC) method is proposed to solve the electromagnetic problems. The proposed DG-RTC method directly discretizes the vector wave equation in each subdomain, and the numerical flux is used for the information communication of solutions between neighbor subdomains. Compared with the traditional Maxwell's equations-based DG (ME-DG) method, the proposed DG-RTC method merely solves the E-field in the whole computational region, while the H-field is only present at the interfaces of adjacent subdomains, which thus significantly reduces the number of unknowns. Moreover, the finalized globally coupled matrix equation is split into …

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Satellite Drag Coefficient Modeling For Thermosphere Science And Mission Operations, Piyush M. Mehta, Smriti N. Paul, Nicholas H. Crisp, Philip L. Sheridan, Christian Siemes, Günther March, Sean Bruinsma Jan 2022

Satellite Drag Coefficient Modeling For Thermosphere Science And Mission Operations, Piyush M. Mehta, Smriti N. Paul, Nicholas H. Crisp, Philip L. Sheridan, Christian Siemes, Günther March, Sean Bruinsma

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Satellite drag modeling remains the largest source of uncertainty affecting space operations in low Earth orbit. The uncertainty stems from inaccurate models for mass density and drag coefficient. Drag coefficient modeling also impacts scientific knowledge on the physics and dynamics of the upper atmosphere through the estimation of high-fidelity mass density from measurements of acceleration on-board satellites. Efforts over the last decade have pushed drag coefficient modeling in the right direction, however, have resulted in multiple methods and tools. We provide a comprehensive review of the drag coefficient modeling methods and tools. Current scale differences between thermospheric data sets mostly …

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Effects Of Wheel Rotation On Long-Period Wake Dynamics Of The Drivaer Fastback Model, Matthew Aultman, Rodrigo Auza-Gutierrez, Kevin Disotell, Lian Duan Jan 2022

Effects Of Wheel Rotation On Long-Period Wake Dynamics Of The Drivaer Fastback Model, Matthew Aultman, Rodrigo Auza-Gutierrez, Kevin Disotell, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice Boltzmann method (LBM) simulations were performed to capture the long-period dynamics within the wake of a realistic DrivAer fastback model with stationary and rotating wheels. The simulations showed that the wake developed as a low-pressure torus regardless of whether the wheels were rotating. This torus shrank in size on the base in the case of rotating wheels, leading to a reduction in the low-pressure footprint on the base, and consequently a 7% decrease in the total vehicle drag in comparison to the stationary wheels case. Furthermore, the lateral vortex shedding experienced a long-period switching associated with the bi-stability in …

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Comparison Of Mechanical And Column Flotation Performances On Recovery Of Phosphate Slimes In Presence Of Nano-Microbubbles, Fatemeh Taghavi, Mohammad Noaparast, Ziaeddin Pourkarimi, Fardis Nakhaei Jan 2022

Comparison Of Mechanical And Column Flotation Performances On Recovery Of Phosphate Slimes In Presence Of Nano-Microbubbles, Fatemeh Taghavi, Mohammad Noaparast, Ziaeddin Pourkarimi, Fardis Nakhaei

Mining Engineering Faculty Research & Creative Works

Fine particle flotation has been one of the main problems in many mineral processing plants. The bubble-particle collision rate is very low for fine particles, which reduces flotation efficiency. Also, the existence of slimes is, generally, detrimental to the flotation process, affecting the selectivity and the quality of the concentrates. Besides, it causes an increase in reagents consumption. Hence, in most of processing plants, some of these particles are transmitted to the tailing ponds to reduce the effects of these problems and increase the selectivity of the process. Esfordi phosphate plant in Iran loses more than 30% of its capacity …

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Acute Magnetic Resonance Imaging Predictors Of Chronic Motor Function And Tissue Sparing In Rat Cervical Spinal Cord Injury, Seung-Yi Lee, Brian D. Schmit, Shekar N. Kurpad, Matthew D. Budde Jan 2022

Acute Magnetic Resonance Imaging Predictors Of Chronic Motor Function And Tissue Sparing In Rat Cervical Spinal Cord Injury, Seung-Yi Lee, Brian D. Schmit, Shekar N. Kurpad, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Predicting functional outcomes from spinal cord injury (SCI) at the acute setting is important for patient management. This work investigated the relationship of early magnetic resonance imaging (MRI) biomarkers in a rat model of cervical contusion SCI with long-term functional outcome and tissue sparing. Forty rats with contusion injury at C5 at either the spinal cord midline (bilateral) or over the lateral cord (unilateral) were examined using in vivo multi-modal quantitative MRI at 1 day post-injury. The extent of T2-weighted hyperintensity reflecting edema was greater in the bilateral model compared with the unilateral injury. Diffusion tensor imaging (DTI) …

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Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung Jan 2022

Dual-Band Decoupling Network For Mimo Antennas, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel method to design a decoupling network (DN) to increase isolation between dual-band antennas. The DN design is based on the scattering matrix and optimized by the Genetic Algorithm (GA). The decoupling example shows that the DN offers impedance matching and high isolation within desired bands, verifying the concept.

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Guest Editorial, Ming Yu, Lijun Jiang, Alex M.H. Wong Jan 2022

Guest Editorial, Ming Yu, Lijun Jiang, Alex M.H. Wong

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A Fast Awe-Augmented Wideband Discontinuous Galerkin Frequency-Domain Method In Solving Electromagnetic Wave Equations, Shi Min Liu, Li (Lijun) Jun Jiang, Ping Li Jan 2022

A Fast Awe-Augmented Wideband Discontinuous Galerkin Frequency-Domain Method In Solving Electromagnetic Wave Equations, Shi Min Liu, Li (Lijun) Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this research, a discontinuous Galerkin frequency-domain (DGFD) method is proposed to solve the electromagnetic wave equations. Different to the explicit time-domain analysis, the electric-field and magnetic-field in frequency-domain wave equations are coupled together implicitly, thus the established matrix equation is globally coupled, which is computational expensive if solving it directly. To address this issue, a Block-diagonal preconditioner and a restriction operator are applied to the matrix equation, which splits the global matrix into a number of small local matrix systems pertinent to each subdomain. Then, a direct solver can be employed to solve them with a FETI-like procedure. Besides, …

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Modeling Radiated Emissions From Pcbs In Shielding Enclosures Based On A Numerical Green's Function Approach, Zi An Wang, Li (Lijun) Jun Jiang, Jun Fa Mao, Ping Li Jan 2022

Modeling Radiated Emissions From Pcbs In Shielding Enclosures Based On A Numerical Green's Function Approach, Zi An Wang, Li (Lijun) Jun Jiang, Jun Fa Mao, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

To accurately and efficiently model the radiated emissions from printed circuit boards (PCBs) placed in shielding enclosures, in this work, a novel approach based on the numerical Green's function (NGF) is proposed. In terms of Schelkunoff's equivalence principle, if the interior of the shielding enclosure is filled up with perfectly electric conductor (PEC), only tangential electric fields over the ventilation slots are sufficient to obtain the radiated emissions. However, due to the presence of the PEC filled shielding box, the in-situ Green's function is not available. To conquer this problem, the proposed approach can be split into two steps. In …

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Supporting Green Neuromorphic Computing: Machine Learning Guided Microfabrication For Resistive Random Access Memory, Abdi Yamil Vicenciodelmoral, Md Mehedi Hasan Tanim, Feng Zhao, Xinghui Zhao Jan 2022

Supporting Green Neuromorphic Computing: Machine Learning Guided Microfabrication For Resistive Random Access Memory, Abdi Yamil Vicenciodelmoral, Md Mehedi Hasan Tanim, Feng Zhao, Xinghui Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

The growing popularity of big data and machine learning applications call for a more powerful and energy-efficient way to execute deep learning workflows. Neuromorphic chips provide a potential solution, as they attempt to mimic the neuronal architectures in human brain and show great potentials in reducing energy consumption in the order of magnitude and also improve the computational performance. However, the fabrication process for neuromorphic chips is costly and currently based on trial-and-error, which adds complexity to the design process. In this paper, we address this challenge by designing and developing machine learning guided microfabrication process for Resistive Random Access …

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Autonomous Coffee Brewing System, Lillian Gonzalez, Landon Miller, Tyler Moff, Benjamin Vitu Jan 2022

Autonomous Coffee Brewing System, Lillian Gonzalez, Landon Miller, Tyler Moff, Benjamin Vitu

Williams Honors College, Honors Research Projects

Coffee consumers want an affordable, high-quality cup of coffee that takes minimal time to brew and does not excessively contribute plastic to landfills. A fully autonomous system which utilizes whole coffee beans, water, and filters to brew coffee was designed to meet this need. This system accepts user requests which specify the brew’s portion size, water temperature, and brew strength, as well as the time which the system should begin the brewing process. Occasional maintenance to empty the system’s built-in waste receptacle or resupply the system with water, coffee beans, or filters is the only user intervention required. This report …

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Comparative Analysis Of Bridge Abutment Types, David Fell Jan 2022

Comparative Analysis Of Bridge Abutment Types, David Fell

Williams Honors College, Honors Research Projects

This project was developed to serve as a brief overview of design practices and considerations in the selection of highway bridge abutment types. This involved a review of literature in the form of reviewing national design guides and department of transportation (DOT) requirements from both US DOTs and international DOTs. The abutment types covered in this research included conventional reinforced concrete abutments with bearings, integral abutments, and semi-integral abutments. This research focused solely on highway bridge abutments, particularly on Ohio Department of Transportation design requirements due to their extensive use of semi-integral abutments. Superstructure elements and geometric requirements are primary …

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Prototype Development For Fabric Sodium Sensor, Mary Nicodemus, Dunia Jaffal, Shelby Daniels Jan 2022

Prototype Development For Fabric Sodium Sensor, Mary Nicodemus, Dunia Jaffal, Shelby Daniels

Williams Honors College, Honors Research Projects

This project is designed to refine a process for developing sodium-selective nylon fabric sensors to be used for reading sodium concentrations in sweat from the human body through a series of quality control and on-body testing experiments. The intention is to have a refined process to make reproducible sensors that are turned into consistently working prototypes for future mass production. There are three essential steps in developing a working prototype: sensor synthesis, sensor testing, and sensor validation. Once all three steps are completed, consistent methods will be defined for turning nylon into sensors and then into prototypes, calibrating the prototypes, …

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Schaeffler F-250 Bev Conversion: Power Electronics, Leslie Sawyer Jan 2022

Schaeffler F-250 Bev Conversion: Power Electronics, Leslie Sawyer

Williams Honors College, Honors Research Projects

This report shows the work that was done on the power electronics system in the industry sponsored Schaeffler demonstration truck project. The goal of the project was to convert a combustion Ford F250 into a battery electric vehicle, while using as much Schaeffler technology as possible. After the vehicle is converted it will be used as a demonstration vehicle to show potential investors. While this project is still in progress, the work that was done during this time was substantial to the development of this project. Progress that has been made on the power electronics system includes developments in selecting …

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Austenitic, Duplex, And Lean Duplex Stainless Steel Critical Pitting Temperature In Simulated Concrete Environment, Bobby Giebel Jan 2022

Austenitic, Duplex, And Lean Duplex Stainless Steel Critical Pitting Temperature In Simulated Concrete Environment, Bobby Giebel

Williams Honors College, Honors Research Projects

In this work, the critical pitting temperature (CPT) will be observed for a selection of austenitic (316LN and 24100) and duplex (2205), and lean duplex (2304, 2001) stainless steels in simulated concrete pore solution. To study the influence of temperature on the pitting stability of the stainless steels, three temperatures were tested: 25oC, 45oC, and 65oC for cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS). Electrochemical properties of the interfaces we studied via EIS analysis. Kinetics were studied via CPP testing. To reveal the critical pitting temperature of the stainless steels, cyclic thermammetry was used. Characterization of the pits …

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Quickcut Waterjet Cutter, Kennedy Dunn, Jacob Storrow, Benjamin Laughrey Jan 2022

Quickcut Waterjet Cutter, Kennedy Dunn, Jacob Storrow, Benjamin Laughrey

Williams Honors College, Honors Research Projects

The QuickCut Waterjet Cutter was created in 2019 as a senior design project. This is the third iteration of the waterjet cutter. The goal of this project was to create an operable CNC waterjet cutter that is able to cut 1/16” tensile specimens consisting of nonferrous metal or plastic. This machine will be utilized in the Manufacturing Laboratory at the University of Akron to provide education to interested students on the waterjet cutting process, how it operates, and industrial application of the technology. Waterjet cutting is a subtractive manufacturing process which is recognized for its specialized applications such as cutting …

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Novel Natural Language Processing Models For Medical Terms And Symptoms Detection In Twitter, Farahnaz Golrooy Motlagh Jan 2022

Novel Natural Language Processing Models For Medical Terms And Symptoms Detection In Twitter, Farahnaz Golrooy Motlagh

Browse all Theses and Dissertations

This dissertation focuses on disambiguation of language use on Twitter about drug use, consumption types of drugs, drug legalization, ontology-enhanced approaches, and prediction analysis of data-driven by developing novel NLP models. Three technical aims comprise this work: (a) leveraging pattern recognition techniques to improve the quality and quantity of crawled Twitter posts related to drug abuse; (b) using an expert-curated, domain-specific DsOn ontology model that improve knowledge extraction in the form of drug-to-symptom and drug-to-side effect relations; and (c) modeling the prediction of public perception of the drug’s legalization and the sentiment analysis of drug consumption on Twitter. We collected …

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Radial Artery Model For Catheterization Procedures, Kyla Beville, Mitchell Gagnon, Benjamin Stalls, Maya Ariza Jan 2022

Radial Artery Model For Catheterization Procedures, Kyla Beville, Mitchell Gagnon, Benjamin Stalls, Maya Ariza

Williams Honors College, Honors Research Projects

The purpose of this project was to create a radial artery model that is usable under ultrasound that would reduce complications during catheterization procedures. Each year, over one million of these procedures are done and complications can affect the outcomes of the patient. Using ultrasound during these procedures is an upcoming way to reduce these complications and improve the outcome that a patient will have.

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Further Exploration Of Optical/Thermal Interaction Effects On High-Power Laser System Performance And Optimization Through Multiphysics System-Level Modeling, Nathaniel J. Butt Jan 2022

Further Exploration Of Optical/Thermal Interaction Effects On High-Power Laser System Performance And Optimization Through Multiphysics System-Level Modeling, Nathaniel J. Butt

Browse all Theses and Dissertations

High-power laser systems (HPLS) have wide-ranging applications in many prominent areas. HPLS use laser diodes to pump fiber gain media. Understanding the functionality of both components is critical for achieving effective HPLS operation. System optical efficiency is a function of diode junction temperature. As junction temperature changes, the wavelength spectrum of the diode output shifts causing optical power losses in the fiber gain media. Optical/thermal interactions of the dynamically coupled laser diodes and fiber gain media are not fully understood. A system level modeling approach considering the interactions between optical performance and component temperature is necessary. Four distinct models were …

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The Effects Of Geometry And Architecture Of Polymer Matrix Composites On Acoustic Emissions, John J. Bush, Alex D. Swartzentruber, Lukas B. Thompson, Sarah R. Pratt, Chris J. Kuhn Jan 2022

The Effects Of Geometry And Architecture Of Polymer Matrix Composites On Acoustic Emissions, John J. Bush, Alex D. Swartzentruber, Lukas B. Thompson, Sarah R. Pratt, Chris J. Kuhn

Williams Honors College, Honors Research Projects

The purpose of this project is to study how the variance of the geometry and architecture of polymer matrix composites (PMCs) affect the acoustic emissions measured whilst said structures are subjected to tensile stress. In these tests, a method called Modal AE will be utilized. In Modal AE, some relationships between sources and waves in various materials and geometries are presented in other papers/research. This study will focus on how different thickness and different makeup/ply patterns affect the acoustic emission tests. Some research has been completed and shown how energy attenuation affects the frequency content on PMCs similar to the …

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Liquid Engine External Pressurizer (Leep), Emily Armbrust Jan 2022

Liquid Engine External Pressurizer (Leep), Emily Armbrust

Williams Honors College, Honors Research Projects

The purpose of this project is to take the current liquid rocket engine test stand design and implement an external pressurant instead of utilizing the 2-phase oxidizer vapor to pressurize itself and the fuel. The purpose behind the design is because the team is limited with the current design concerning burn time due to the amount of propellant they can put in the tanks and the pressure it can reach. The initial pressure is currently not held since there is no external input of mass into the tanks, as the propellant is leaving. Adding an external pressurant allow for the …

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Additive Manufacturing Waste Management System - Plastic Extrusion Process, Gabriel Bennett, Lindsay Liebrecht, David Lyogky, Wilson Woods Jan 2022

Additive Manufacturing Waste Management System - Plastic Extrusion Process, Gabriel Bennett, Lindsay Liebrecht, David Lyogky, Wilson Woods

Williams Honors College, Honors Research Projects

3D printing is a fast-growing market with its main source of waste being PLA and ABS plastics. In 2019, the global additive manufacturing market grew to over $10.4 billion, crossing the pivotal double-digit billion threshold for the first time in its nearly 40-year history. (SmarTech Analysis, 2020 Additive Manufacturing Market Outlook and Summary of Opportunities Report). The waste is generated from failed prints and rejected support structures which are common occurrences for personal use. Plastic recycling has become one of the leading discussions of environmental protection and waste management. The 3D market currently does not offer an effective and affordable …

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