Engineering Commons^™

Dynamic Friction Measurements Of Egyptian Cotton Yarns Part 2: Study Of Frictional Behavior Of Plyed Yarns., M. Salama, R. El-Bealy, S. Ibrahim

Mansoura Engineering Journal

In this work the frictional properties of single and plyed yarns were studied. The yarn coefficient of friction was found to be affected by the sliding speed over guides, yarn count and guide diameter. The method of twisting (ring or two-for-one) was also found to have a substantial influence on the friction behavior of plyed yarns.

Identifying The Need For Trained Machinists In The Greater Tri-Cities Area, Bradley Stufflestreet

Electronic Theses and Dissertations

Machinists are skilled tradespeople responsible for running a variety of machine tools to produce precision components for end-users or use in other manufacturing. This project identifies the current and future change in the number of machinists in the Tri-Cities area, especially the five-county service area of Northeast State Community College. Using an industry survey, the need for machinists is identified and evaluated to understand local employers’ needs. The results indicate industry needs more machinist to keep up with demand, as 6 out of 14 companies have open positions and, 8 reported difficulty filling openings. Furthermore, most companies are growing or …

A Comparison Of Methods To Measure Crop Water Use In South Carolina, Andrew C. Ewing

All Theses

The objective of this thesis was to compare cost-effective methods of measuring crop water use, known as evapotranspiration (ET), in South Carolina’s humid climate. The methods analyzed were the surface renewal method (SR), the Eddy Covariance method (EC), large in-field weighing lysimeters, a newly developed pressure differential device (PDD), a Class A Evaporation pan, and the Penman-Monteith equation. In the first chapter, ET measurements obtained by SR were compared to ET measured by EC and weighing lysimeters. For reference, EC and SR track the energy budget to estimate ET, while the weighing lysimeters used in this study are box-like containers …

Ultrafast Spin-Currents And Charge Conversion At 3d-5d Interfaces Probed By Time-Domain Terahertz Spectroscopy, T. H. Dang, J. Hawecker, E. Rongione, G. Baez Flores, D. Q. To, J. C. Rojas-Sanchez, H. Nong, J. Mangeney, J. Tignon, F. Godel, S. Collin, P. Seneor, M. Bibes, A. Fert, M. Anane, J. M. George, L. Vila, M. Cosset-Cheneau, D. Dolfi, R. Lebrun, P. Bortolotti, Kirill Belashchenko, S. Dhillon, H. Jaffrès

Kirill Belashchenko Publications

Spintronic structures are extensively investigated for their spin-orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-Transition metal interfaces due to their inverse spin-Hall effect properties. In particular, the intrinsic inverse spin-Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques-ultrafast THz time-domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping …

Development Of A Single Emitter Ionic Liquid Ion Source Research Platform, Thomas V. Kerber

Masters Theses

A single emitter ionic liquid ion source using porous borosilicate glass was developed. Two emitters with different radii of curvatures were tested using 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF₄). I-V curves of the currents on the extractor electrode and a collector plate were obtained for potential differences between the emitter and the extractor ranging from 0 V to 3500 V. For the first emitter chip, extraction began near 2400 V. The highest emission current measured on the first chip was 80 µA at 3500 V with an interception current on the extractor of 4.86 µA. An new collector plate was used …

Synthesis And Characterization Of Non-Pgm Catalysts For Fuel Cell Applications, Sudharsan Sridhar

Masters Theses

Fuel Cells convert the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. Proton Exchange Membrane (PEM) fuel cells convert (efficiency-60%) hydrogen and air to power the electric motors with zero emissions, facilitating the development of environmentally friendly and sustainable automobile technologies. One of the major obstacles for larger commercial viability of Fuel Cells for automobile applications is their cost-effectiveness. Currently, fuel cells use platinum as a catalyst material, which is prohibitively expensive for commercial automobile applications. The development of non-Platinum Group Metal (non-PGM) catalyst materials with similar electrochemical performance to that …

The Feasibility Of Real Time Location Systems In Construction, John O. Brouse Iv

Construction Management

The construction industry is becoming increasingly sophisticated by implementing new computer-based technologies to improve safety, efficiency, accountability, and many other aspects. One new type of technology that is becoming increasingly popular in other labor based industries is real time locating systems. These systems allow for managers to keep accountability of a variety of assets in a manufacturing facility or industrial center. Recent research has shown the benefits and potential uses of these systems on construction jobsites. This paper seeks to analyze the potential for Real Time Location Systems (RTLS) to be used on construction jobsites and compare the different RTLS …

Blockchain Technology In The Construction Industry, Marco C. Reza

Construction Management

The construction industry has not advanced as quickly as other industries in the aspects of time, cost, and quality; but Blockchain could be the solution. While there have been improvements in the construction sector such as BIM or Prefabrication, nothing compares to those in other industries. This brings the search for a new technology that would boost construction to a new level of productivity. One technology that could potentially do this is Blockchain. Blockchain, defined in a big picture, is like a shared google sheet where anybody could add information but nobody could delete it. This technology could change the …

Understanding Culture Within The Construction Industry Through Lifelong Learning (Slo 24), Skylar Schrank

Construction Management

Understanding cultural differences is a crucial step for the success of a construction firm. Creating a common ground for diversifying the perspectives of individuals in the construction industry will prove to progress the success of a company and the projects that are a part of these firms. This study guide will define what culture means for construction, the different types of cultures in the construction industry, as well as how to implement cultural background in our education for cultural understanding. The result will be an understanding on how culture poses a risk to construction and how these risks can be …

Robust Maximum Coverage Facility Location Problem With Drones Considering Uncertainties In Battery Availability And Consumption, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

Given a set of spatially distributed demand for a specific commodity, potential facility locations, and drones, an agency is tasked with locating a prespecified number of facilities and assigning drones to them to serve the demand while respecting drone range constraints. The agency seeks to maximize the demand served while considering uncertainties in initial battery availability and battery consumption. The facilities have a limited supply of the commodity being distributed and also act as a launching site for drones. Drones undertake one-to-one trips (from located facility to demand location and back) until their available battery energy is exhausted. This paper …

Spatially Directed Functionalization By Co-Electropolymerization Of Two 3,4-Ethylenedioxythiophene Derivatives On Microelectrodes Within An Array, Benjamin J. Jones, Carol Korzeniewski, Jefferson H. Franco, Shelley D. Minteer, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

Electrodeposited conductive copolymer films with predictable relative properties (quantities of functional groups for further modification and capacitance) are of interest in sensors, organic electronic materials and energy applications. Potentiodynamic copolymerization of films in aqueous solutions of two different thiophene derivatives, (2,3-dihydrothieno[3,4-b]dioxin-2-yl) methanol (1) and 4-((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)-methoxy)-4-oxobutanoic acid (2), containing 0.02 M total monomer (0, 25, 34, 50, 66, 75, 100 mol% 2), 0.05 M sodium dodecyl sulfate, and 0.1 M LiClO4, on gold microelectrodes in an array was investigated. Decreasing monomer deposited (m) from 0 to 100 mol% 2 is attributed to a decreasing pH that inhibits electropolymerization. Molar ratios of …

Strain Control Of Layer-Resolved Negative Capacitance In Superlattices, Raymond Walter, Sergey Prosandeev, Charles Paillard, L. Bellaiche

Physics Faculty Publications and Presentations

Negative capacitance in BaTiO₃/SrTiO₃ superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model, using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields. We show that epitaxial strain can tune the negative capacitance of the BaTiO₃ ferroelectric layer and the overall capacitance of the system. In addition, we predict and explain an original switching of the negative capacitance from the BaTiO₃ layer to the SrTiO₃ layer at low temperatures for intermediate strains.

2020 Summer-Fall Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for summer and fall 2020. Includes photographs, upcoming events, recent publications, and student profiles.

Effects Of Ca Doping On Structural And Optical Properties Of Pzt Nanopowders, K. H. Omran, M. Mostafa, M. S. Abd El-Sadek, O. M. Hemeda, R. Ubic

Materials Science and Engineering Faculty Publications and Presentations

The influence of the addition of calcium ions (Ca²⁺) in the Pb_(1-x)Ca_xZr_0.52Ti_0.48O₃ system (PCZT) for x = 0.05, 0.10, 0.15, 0.20, and 0.25 on the structural and optical properties was systematically studied. The compositions were synthesized through a polymerized-complex approach based on the Pechini polymeric precursor route. The solubility limit of calcium ions within the PCZT lattice is in between x = 0.10 and x = 0.15, at which a CaTiO₃ secondary phase is detected. The Goldschmidt tolerance factors, modified tolerance factors, and the effective vacancy sizes were …

Vibration Analysis Of Simultaneous Drilling And Reaming Bha, Mohammed F. Al Dushaishi, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The drillstring used in the oil and gas exploration is a complex structure due to the different forces acting on it. One of the primary sources of drillstring vibrations is the cutting forces caused by the drill bit contact with the rock formation. In some drilling applications, such as hole enlargement and underreaming, the source of the cutting action originates from the drill bit as well as the reamer which increases the dynamic complexity of the drillstring. This paper’s objective is to investigate the torsional vibration behaviors of the bottom hole assembly (BHA) under simultaneous drilling and reaming. More specifically, …

Characterization Of A Packaged Triboelectric Harvester Under Simulated Gait Loading For Total Knee Replacement, Nabid Aunjum Hossain, Geofrey George Yamomo, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Load sensing total knee replacement (TKR) implants are useful tools for monitoring prosthesis health and providing quantitative data to support patient claims of pain or instability. Powering such devices throughout the entire life of the knee replacement, however, is a challenge, and selfpowered telemetry via energy harvesting is an attractive solution. Herein, we implemented vertical contact mode triboelectric energy harvesters inside a knee implant package to generate the power required for embedded digitization and communications circuitry. The harvesters produce small-scale electric power from physiologically relevant loads transmitted through the knee. Experiments were performed on a joint motion simulator with an …

High Performance Thermal Straps For A Full Range Of Application Temperatures, M. Ralphs, M. Sinfield, M. Felt

Space Dynamics Laboratory Publications

Thermal straps are an essential component when using vibration sensitive instruments and cryocoolers in close proximity. Thermal straps conduct heat from the instrument to the cryocooler while limiting the amount of mechanical vibration the cryocooler transfers back to the instrument. Thermal straps are made from flexible, thermally conductive materials. Traditionally, they are made of metal – aluminum or copper, mostly – that has been formed into thin foils, wires, or braids to provide greater flexibility while still providing good thermal conductivity. These metallic straps, if made from pure metals, provide superior thermal performance at cryogenic temperatures ( < 60 K ) where their thermal conductivities peak to extraordinary levels. Pyrolytic graphite sheet (PG S) thermal straps have a thermal conductance that peaks at higher temperatures – approximately 160 K – and provide much higher mass-specific thermal conductance at temperatures above 60 K than metallic straps. This paper discusses the pros and cons of aluminum, copper, and PG S thermal straps along with different techniques to test their thermal and mechanical performance.

Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford

Theses and Dissertations

This study is an investigation of various methods for recharging a micro autonomous underwater vehicle (μAUV) onboard using renewable energy sources while deployed at sea. The goal of this project is to determine the optimal onboard renewable energy design method to be used to prolong the deployment life of a μAUV. This project specifically targeted vehicles specifications and designs similar to the Riptide Autonomous Solutions’ μAUV[1], which was used for this study. Concluding results are based on the following factors: power generation versus time, structural integrity, and design complexity. The three design method categories investigated are as follows: solar energy, …

Development Of A Deformation-Based Structural Health System With Contactless Sensors And Machine Learning For Health Characterization And Failure Prediction, Juan Camilo Avendano Arbelaez

Theses and Dissertations

This dissertation presents the design and development of a structural health monitoring (SHM) system specifically tailored for transportation infrastructure components, such as bridges. The proposed system collects data by using contactless sensors and performs health characterization and failure prediction. It is capable of simulating multiple load conditions on structures, identifying possible failure points, and detecting and predicting failure scenarios. Both hardware and software implementations of a model of a bridge were performed as a pilot project in order to validate the proposed system. Computer simulation in ANSYS and the application of gradient boosting neural networks were performed to produce a …

Development And Application Of Sustainable Binders Comprising Of Fly Ash And Ground Glass Fibers In Portland Cement And Geopolymer Concrete, Omar Alsanusi Amer

All Dissertations

Since cement production is responsible for a significant share of anthropogenic CO2 emissions, the sustainability of concrete construction has become one of the most targeted research and construction industry goals. Many suggestions have been in use to encourage sustainability of concrete construction; one such approach is to partially replace cement by industrial byproducts. The most known industrial byproduct used in concrete construction worldwide has been fly ash, which is a byproduct of burning coal for power generation.

Fly ash use in concrete has various benefits. It reduces the water demand, reduces plastic shrinkage, reduces permeability, and thus improving the durability …

Me-Em Enewsbrief, October-December 2020, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Analysing User Experience Of Mobile Banking Applications In Nigeria: A Text Mining Approach, Omotosho Babatunde S.

CBN Journal of Applied Statistics (JAS)

This paper analyses textual data mined from 37,460 reviews written by mobile banking application users in Nigeria over the period November 2012 – July 2020. On a scale of 1 to 5 (5 being the best), the average user rating for the twenty-two apps included in our sample is 3.5; with the apps deployed by non-interest banks having the highest average rating of 4.0 and those by commercial banks with national authorisation having the least rating of 3.4. Results from the sentiment analysis reveal that the share of positive sentiment words (17.8%) in the corpus more than double that of …

Optimizing Energy Power Consumption Of Freight Railroad Bearings Using Experimental Data, Carlos Eliasar Lopez Iii

Theses and Dissertations

Throughout the railway industry, trains use systems that record total energy efficiency of a train but not energy efficiency or consumption by components. Monitoring freight bearing power consumption can support the railroad industry efforts to maintain the railroad economic competitiveness and minimize the environmental impact.

For more than a decade now, the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV) has been collecting power consumption data for railroad bearings under various loads, speeds, ambient temperatures, bearing condition, and bearing classes. Specifically, data such as temperatures, voltages, speed, and load were collected to …

Water-Soluble Polymers With Ceramic/Metal Nanoparticles For Use As Anode Materials In Lithium-Ion And Sodium-Ion Batteries, Roberto Orrostieta Chavez

Theses and Dissertations

Aqueous solutions of poly(vinylpyrrolidone) (PVP) with 20, 25, and 28 wt.% concentrations were successfully spun into fibers by centrifugal spinning. The pristine PVP fibers were annealed and carbonized to produce flexible carbon fibers for use as binder-free anodes in lithium-ion and sodium-ion batteries. These flexible carbon fibers were prepared by developing a novel three-step heat treatment to reduce the residual stresses in the pristine PVP precursor fibers and to prevent fiber degradation during carbonization. The average diameters of the pristine, annealed, and carbonized fibers were obtained using scanning electron microscopy (SEM), which showed that the average diameter of the carbon …

A Study On The Triaxial Shear Behavior Of Geosynthetic Reinforced Soil By Discrete Element Method, Md Wasif Zaman

Theses and Dissertations

A 3D DEM model using Particle Flow Code (PFC3D) software was developed utilizing a bonded-ball flexible membrane approach to study cohesionless soil as a discontinuous discrete material. The 3D model was calibrated and verified with experimental data, and a sensitivity analysis was carried out for the microparameters. Triaxial tests were simulated to observe the stress-strain curves and volumetric changes, as well as the strength parameters of soils consisting of spherical particles with different gradations but the same porosity. One important finding is that the relationships between particle size and deviatoric stress, internal friction angle, and dilatancy angle were found to …

Microsoft’S Surface Pro 4 Performance Under Denial Of Service Attack, Adrian Guerrero

Theses and Dissertations

Microsoft Surface Pro 4 (SP4) is a new device in the line of hybrid computers today. It aims to work as both as table and laptop computer. There are multiple versions of SP4 that include devices equipped with i3, i5 and i7 core processors.

This makes SP4 a great addition for hospital, clinics or schools for its portability and features. As these locations can be prone to cyber-attacks, we plan to test this computer’s reliability and performance under cybersecurity attacks. The device tested is built with Intel Core i7-6650U 2.21 GHz processor with automatic overclocking capabilities up to 3.4 GHz, …

The Integration Of Iterative Convergent Photogrammetric Models And Uav View And Path Planning Algorithms Into The Aerial Inspection Practices In Areas With Aerial Hazards, Michael James Freeman

Theses and Dissertations

Small unmanned aerial vehicles (sUAV) can produce valuable data for inspections, topography, mapping, and 3D modeling of structures. Used by multiple industries, sUAV can help inspect and study geographic and structural sites. Typically, the sUAV and camera specifications require optimal conditions with known geography and fly pre-determined flight paths. However, if the environment changes, new undetectable aerial hazards may intersect new flight paths. This makes it difficult to construct autonomous flight path missions that are safe in post-hazard areas where the flight paths are based on previously built models or previously known terrain details. The goal of this research is …

Development Of A Self-Powered Weigh-In-Motion System, Athanassios Papagiannakis, Sarah Ahmed, Samer Dessouky, Reza Khalili, Gopal Vishwakarma

Publications

This report describes the development of a novel weigh-in-motion (WIM) system that utilizes piezoelectric elements for sensing load and powering an ultra-low power microcontroller unit (MCU) that serves as its data acquisition system. A system of 4 piezoelectric (PZT) stacks serves as the energy harvester, while load sensing is done via a set of 4 PZT elements connected in parallel. Two alternative MCUs were considered, with various data handling capabilities and power consumption requirements. These MCUs have very short “wake-up” times allowing vehicle sensing without the need for inductive loops commonly used in conventional WIM systems. Special electric circuits were …

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The Green's function retrieval in media with horizontal boundaries usually only considers the extraction of direct and reflected waves but ignores the virtual head waves, which have been observed experimentally from ocean ambient noise and used to invert for geometric and environmental parameters. This paper derives the extraction of virtual head waves from ocean ambient noise using a vertically spaced sensor pair in a Pekeris waveguide. Ocean ambient noise in the water column is a superposition of direct, reflected, and head waves. The virtual head waves are produced by the cross-correlations between head waves and either reflected waves or other …

Speaker Prototyping Design, Andrew Lathe

Undergraduate Honors Theses

Audio design is a pertinent industry in today’s world, with an extremely large market including leaders such as Bose, Harman International, and Sennheiser. This project is designed to explore the processes that are necessary to create a new type of product in this market. The end goal is to have a functioning, high–quality set of speakers to prove various concepts of design and prototyping.

The steps involved in this project go through the entire design process from initial choice of product to a finished prototype. Processes include the selection of outsourced components such as drivers and necessary connectors. The design …