Structural Materials Commons^™

Phase-Field Models For Simulating Physical Vapor Deposition And Microstructure Evolution Of Thin Films, James Stewart Jr.

Graduate Theses and Dissertations

The focus of this research is to develop, implement, and utilize phase-field models to study microstructure evolution in thin films during physical vapor deposition (PVD). There are four main goals to this dissertation. First, a phase-field model is developed to simulate PVD of a single-phase polycrystalline material by coupling previous modeling efforts on deposition of single-phase materials and grain evolution in polycrystalline materials. Second, a phase-field model is developed to simulate PVD of a polymorphic material by coupling previous modeling efforts on PVD of a single-phase material, evolution in multiphase materials, and phase nucleation. Third, a novel free energy functional …

Measuring Relative Humidity In Concrete Pavements As A Method To Assess Asr Mitigation Measures, Remington G. Reed

Civil Engineering Undergraduate Honors Theses

Alkali-silica reaction (ASR) in concrete is partly facilitated by available moisture within the concrete. In order to better understand this facilitation and to develop processes for ASR mitigation methods, it is necessary to establish a means of monitoring internal relative humidity (RH) within the concrete. Current procedures for measuring RH are time consuming; requiring several hours of equilibration time and specific external conditions to yield accurate results. In order to better understand RH monitoring, laboratory tests were conducted using commercially available RH probes and different controlled environments. Probes were carefully monitored and calibrated in controlled environments, and laboratory tests on …

Modeling And Experimental Investigation On The Influence Of Radiation Defects On Helium Behavior In Bcc Iron, Zuya Huang

Masters Theses

Fe-based alloys are important structural materials for both fission and fusion energy. For fusion applications, the challenges of radiation-induced changes in microstructure, properties and performance is further challenged by the concomitant production of helium from (n, alpha) nuclear reactions and fusion reactions. Due to the lack of a volumetric, high flux 14-MeV neutron source, studying these phenomena require the use of computational materials modeling and novel experimental methods. In this thesis, molecular dynamics (MD) simulations was used to investigate the synergistic interactions of helium with prismatic dislocation loops characteristic of those observed in neutron irradiated iron to determine how the …

Creation And Implementation Of An Underwater-Capable Vr Headset Through The Use Of Additive Manufacturing, Matthew D. Meyers, Nathan Sonnenfeld

Human Factors and Applied Psychology Student Conference

No abstract provided.

Optimizing Chemical & Rheological Properties Of Rejuvenated Bitumen, Dominic Nguyen, Hamzeh Haghshenas Fatmehsari, Santosh Kommidi, Yong-Rak Kim

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Bitumen has long been a material used in the construction of roadways, yet new pavement only consists of low fractions of recycled materials due to poor compatibility of aged bitumen and new materials. Thus, rejuvenators, chemical additives, have been used in an attempt to re-balance the chemical composition and restore the physical properties of aged bitumen back to its virgin state. A fundamental understanding of how one particular rejuvenator, soybean oil, revitalizes bitumen was investigated using a multi-scale approach.

Fourier-transform infrared spectroscopy (FTIR) was used to determine the changes in chemical properties of pure and rejuvenated virgin and aged samples. …

Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz

Masters Theses

Solar technology has been a major topic in sustainable design for many years. In the last five years, however, the solar technology industry has seen a rapid growth in installations and technological advances in cell design. Combined with a rapidly declining overall system cost, the idea of introducing solar technology into a wider range of applications is becoming a focus for engineers and scientists around the world. So many variables which alter solar energy production, such as the sun and surrounding environment, determine whether a solar design is beneficial. This thesis presents a bridge deck surface integrated with solar cells …

Solution, Interfacial, And Interlayer Studies Of Electronically Active Polymers, Hsin-Wei Wang

Doctoral Dissertations

This thesis describes the solution behavior and interfacial properties of electronically active polymers. The performance of such polymers in devices is often determined by their chain conformation and morphology in solution and in thin films. For example, the intricate balance between polymer domain size and crystalline packing of electron donor and acceptor components, as well as the properties at the polymer-metal interface, are crucial for achieving optimal performance in devices, such as solar cells. Chapter 1 presents the current progress in polymer-based solar cells, their fundamental principles, and key factors to improve their efficiency. Literature precedents on the development of …

Bond–Slip Behavior Of Fiber-Reinforced Polymer/Concrete Interface In Single Shear Pull-Out And Beam Tests, Tayyebeh Mohammadi, Baolin Wan, Kent A. Harries

Civil and Environmental Engineering Faculty Research and Publications

It has been assumed that the fiber-reinforced polymer/concrete interface is subjected to in-plane shear condition when intermediate crack debonding failure occurs. Therefore, the single shear pull-out test results are often used to predict the intermediate crack debonding failure in beams. In this study, the behavior of fiber-reinforced polymer-strengthened concrete beams and single shear pull-out specimens were studied experimentally and numerically. The bond–slip behavior of the fiber-reinforced polymer/concrete interface was obtained by single shear pull-out and beam tests. In all beam specimens, a concrete wedge located at the edge of the notch detached with the fiber-reinforced polymer debonding failure. This phenomenon …

Daylighting And Thermo-Electrical Performance Of An Autonomous Suspended Particle Device Evacuated Glazing, Aritra Ghosh

Doctoral

Suspended particle device (SPD) glazing is an AC powered switchable glazing. PV powered SPD evacuated (vacuum) glazing was proposed with the potential of reducing the heating demand, cooling demand and artificial lighting demand of a building. To achieve an autonomous SPD vacuum glazing, semi empirical simulation and outdoor characterisation was explored in this thesis. Transmission of SPD glazing (area 0.058 m2) varied from 5% when opaque to 55% when transparent in the presence of 110 V, 0.07 W AC supply was characterised in outdoor test cell in Dublin. The SPD glazing has variable spectral transmission in the presence of variable …

Application Of Treated Oil Sands Drill Cuttings Waste In Micropiles Construction, Moustafa Ahmed Raafat Mohamed Aboutabikh

Electronic Thesis and Dissertation Repository

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout …

Late Morning Concurrent Sessions: Innovations In Aviation Technologies: Presentation: Relative Material Loss: A Methodology For Assessing Island Airport Steel Marine Bulkheads, Robert Ernsting, Constantine M. Koursaris

Aviation / Aeronautics / Aerospace International Research Conference

A July 2015 report from the Airports Council International – North America (ACI-NA) states “U.S. airports are long overdue for [a] major structural improvement projects. Most U.S. airports are aging, … and because of budgetary restrictions, they’re not aging well.”(Garcia and Clampet, 2015). The average US age is 40 years old with the youngest (Denver International) recently turning 20 years old. As airports continue to age, airport commissioners will struggle to find creative ways to either fund airport replacements or extend the service life of existing airport facilities (commonly referred to as service life extension projects or SLEP). Due to …

Paper Core Feeder System, Sergio Flores Velez

All Undergraduate Projects

Paragon Films has always strived to increase productivity and decrease waist within their company. The plant located in Union Gap, Washington currently has two production lines operating 24/7 managed by 2 to 3 people. The heavy line produces 5000 to 10000 revolutions per roll. This production line has a three part system that automatically feeds the paper cores to the spool shafts to roll the films. Therefore, the employees during that shift do not have to worry about filling up the bin very often. On the other hand, the second production line, which produces the hand films, does not have …

Preliminary Investigation Into The Rate Of Carbonation Of Concrete Blocks Under Normal Production Yard Conditions, Aimee Byrne, Eanna Nolan

Conference papers

The release of CO2 from calcination during the manufacture of cement can be partially or fully offset by the CO2 it naturally absorbs during its lifetime. This paper reports results from a preliminary investigation into the rate of carbonation in concrete blocks stacked in a production yard over a period of 6 months. The blocks were stacked in a normal manner under natural exposure conditions. Carbonation progress was determined by splitting the blocks and spraying the freshly exposed surface with a phenolphthalein solution at intervals over the test period. It was found that the rate of the carbonation front progression …

An Overview Of The Development Of Cement-Based Batteries For The Cathodic Protection Of Embedded Steel In Concrete, Aimee Byrne, Niall Holmes, Brian Norton

Conference papers

This paper presents an overview of the cement-based batteries developed in DIT for use in the cathodic protection of embedded steel in reinforced concrete undergoing chloride-induced corrosion. Cathodic protection delivers an external current (approximately 20mA per m2 of embedded steel) which effectively polarises the internal current generated during corrosion. The batteries developed in DIT comprise of a cement-based electrolyte containing different additives including sand, aggregate, salts, carbon black and plasticiser with protruding anode and cathode metal plates. These batteries produced an initial electrical output of 1.5V and 23mA through a 10 resistor as measured using data acquisition units and a …

Evaluating A New Cem Iii/A Cement For Concretes Exposed To Harsh Acid Rich Environments, David Thompson, Niall Holmes, John Reddy

Conference papers

The Irish Annex to the European specification, performance, production and conformity of concrete, IS EN 206, recommends CEM III/B cement for acid rich environments containing between 66 to 80% GGBS. However, BS 8500, the UK annex to EN 206 and the British Research Establishment (BRE) Special Digest 1, recommends CEM III/A cement with a GGBS range of 36-65%. This project investigated the performance of a new CEM III/A cement produced by Ecocem Ireland in concretes exposed to such environments using an extensive suite of laboratory tests.

In Ireland, up to €5.8bn will be invested to provide fresh drinking water and …

Performance Of Masonry Blocks Containing Different Proportions Of Incinator Bottom Ash, Niall Holmes, Hugh O'Malley, Paul Cribbin, Henry Mullen, Garrett Keane

Articles

No abstract provided.

Design For Fractal Grid Generated Turbulence, Moira Gion

Undergraduate Research & Mentoring Program

Fractal geometry can be used to find organization or order in something that appears to be in disorder, or chaos. Turbulence is viewed as one place where fractal geometry can be found in nature. The irregularity in fluid flow is dependent on the initial conditions. In the past, the idea of self-similarity has been used to develop statistical theories of energy cascade in a turbulent flow. Recent studies have done experiments on obstructing flows with fractal objects to observe intermittency, (or self-similarity) within a turbulent flow. Experiments on fractal grid generated turbulence has been performed by other research groups, so …

Characterization Of Dispersion And Residual Stress In Nanoparticle Reinforced Hybrid Carbon Fiber Composites, Alex Selimov

Honors Undergraduate Theses

Hybrid carbon fiber reinforced composites are a new breed of materials that are currently being explored and characterized for next generation aerospace applications. Through the introduction of secondary reinforcements, such as alumina nanoparticles, hybrid properties including improved mechanical properties and stress sensing capabilities can be achieved. In order to maximize these properties, it is necessary to achieve a homogeneous dispersion of particulate filler. Utilizing the photoluminescent properties of alumina, it is possible to compare local levels of particle concentration through emission intensities as a way to determine the effectiveness of the tested manufacturing parameters in increasing material homogeneity. Parameters of …

Methodology For Analyzing Epoxy-Cnt Phononic Crystals For Wave Attenuation And Guiding, Madhu Kolati

Dissertations, Master's Theses and Master's Reports

Phononic crystals (PhnCs) control, direct and manipulate sound waves to achieve wave guiding and attenuation. This dissertation presents methodology for analyzing nanotube materials based phononic crystals to achieve control over sound, vibration and stress mitigation. Much of the analytical work presented is in identifying frequency band gaps in which sound or vibration cannot propagate through these PhnCs. Wave attenuation and mitigation analysis is demonstrated using finite element simulation. Engineering principles from current research areas of solid mechanics, solid-state physics, elasto-dynamics, mechanical vibrations and acoustics are employed for the methodology. A considerable effort is put to show that these PhnCs can …

Improving The Capacity, Durability And Stability Of Lithium-Ion Batteries By Interphase Engineering, Qinglin Zhang

Theses and Dissertations--Chemical and Materials Engineering

This dissertation is focus on the study of solid-electrolyte interphases (SEIs) on advanced lithium ion battery (LIB) anodes. The purposes of this dissertation are to a) develop a methodology to study the properties of SEIs; and b) provide guidelines for designing engineered SEIs. The general knowledge gained through this research will be beneficial for the entire battery research community.