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2019

Theses/Dissertations

Other Materials Science and Engineering

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Full-Text Articles in Engineering

Effect Of Ion Implantation On The Mechanical Properties Of The Grain And Grain Boundary Regions Of Inconel X750, Maisaa Nezar Tawfeeq Oct 2019

Effect Of Ion Implantation On The Mechanical Properties Of The Grain And Grain Boundary Regions Of Inconel X750, Maisaa Nezar Tawfeeq

Electronic Thesis and Dissertation Repository

Annulus gas spacers in CANada Deuterium Uranium (CANDU) nuclear reactors are made from the heat-treated Inconel X750 Nickel-based alloy. This alloy is designed to have high strength and creep resistance at elevated temperature. Unlike other reactor designs, the CANDU reactor has a high thermal neutron fluence, which results in an enhancement of the radiation damage and the internal production of helium and hydrogen. They are thus susceptible to microstructural instability and mechanical property degradation with time. Studies of ex-service spacers have indicated that they display intergranular embrittlement and lower ultimate tensile strength compared to nonirradiated Inconel X750. The primary degradation ...


Manipulating Fiber Orientation For The Reduction Of Warpage In Carbon Fiber Composite Sandwich Panels, Landon Burnley, Gabrielle Correia Jul 2019

Manipulating Fiber Orientation For The Reduction Of Warpage In Carbon Fiber Composite Sandwich Panels, Landon Burnley, Gabrielle Correia

Materials Engineering

Safran Cabin (Santa Maria, CA), previously known as Zodiac Aerospace, designs and manufactures interior cabin components for private and commercial aircraft. Carbon fiber face sheets have recently been incorporated in their overhead luggage bin assemblies which utilize a composite sandwich panel design, in order to provide additional stiffness to the previous glass fiber sandwich panels. Since the introduction of carbon fiber in these luggage bin panels, Safran has experienced an increase in warpage during manufacturing. When inspected by quality control, the panels are tested mimicking how they are installed in aircraft. If the panels do not meet specifications, the warped ...


Erosion Resistance Of Tungsten-Carbide Coatings For Steel Pipes In Fluid Catalytic Cracking Units, Davis Vannasing, Jennifer Hulfachor Jun 2019

Erosion Resistance Of Tungsten-Carbide Coatings For Steel Pipes In Fluid Catalytic Cracking Units, Davis Vannasing, Jennifer Hulfachor

Materials Engineering

In petroleum processing, the flow of catalyst readily leads to erosion of piping in a fluid catalytic cracking unit. Advances in coating materials and processes necessitate a re-evaluation of current protection methods. Commercially available tungsten-carbide (WC) claddings and nanostructured WC-W CVD coatings were investigated as potential alternative erosion-resistant coatings. Erosion tests by solid particle impingement were conducted on 2 variations of claddings and 1 variation of WC-W coatings following ASTM standard G76. A36 steel coupons were used as reference samples. For statistical validation, 2-3 replications of the tests were performed for the claddings and WC-W coating. Testing was conducted using ...


A Study And Simulation Of Flux Induced Corrosion In Copper Tubing Used For The Distribution Of Potable Water, Daniel O. Benham Jun 2019

A Study And Simulation Of Flux Induced Corrosion In Copper Tubing Used For The Distribution Of Potable Water, Daniel O. Benham

Materials Engineering

Water side corrosion within copper plumbing can occur due to a wide variety of unwanted circumstances. Through the controlled immersion of six ¾” copper tubing samples with five utilizing a unique industry standard soldering flux, this investigation associates residual flux deposits with the initiation of pitting in copper. Water stagnation in a copper potable water distribution system, typically associated with an infrequently used faucet, is a condition highly prone to copper pitting. A test apparatus designed to produce a partially stagnant flow condition with scheduled electrolyte flushes every 3 days was developed and constructed to contain 6 test samples for ...


Investigating The Rapid Curing Possibility Of Geopolymer Concrete, Ashlesh Banjara May 2019

Investigating The Rapid Curing Possibility Of Geopolymer Concrete, Ashlesh Banjara

Master's Theses

Recent studies of heat-cured fly ash based green geopolymer concrete have shown its suitability for fabrication of structural members. Fabrication of these structural members requires continuous moderate heating (145°F) for 24 hrs, and an oven essential, for a large member can quickly turn into an energy guzzler, potentially eliminating the green credentials of the product. The proposed research involves the development of a frontal polymerization (FP) method that achieves rapid curing of geopolymer at ambient condition after short-term heat application. Initial work shows thermal FP in geopolymer is a possibility and might be a solution to the problem. The ...


Fracture Toughness Improvement Of ����� Ceramics By Grain Size Control And Ductile Phase Reinforcement, Kesong Wang May 2019

Fracture Toughness Improvement Of ����� Ceramics By Grain Size Control And Ductile Phase Reinforcement, Kesong Wang

Engineering and Applied Science Theses & Dissertations

This study used grain size control and ductile phase reinforcement to improve fracture toughness of ����� ceramics. Alpha alumina particles of 100 nm, 0.5-1 micrometers, and 10 micrometers were coated with 1-5 nm nickel by electroless nickel plating (ENP). The coated powders were consolidated at 1200℃-1500℃ by spark plasma sintering (SPS). The sintered samples were annealed at 1100 oC for 1.5 hours and 10 hours to determine the effect of post sintering annealing on hardness and fracture toughness. Density of the samples were measured by the standard Archimedes method using a 5 mL pycnometer. Hardness values were determined ...


Additive Manufacturing Of High Performance Flexible Thermoelectric Generators Using Nanoparticle Inks, Tony Valayil Varghese May 2019

Additive Manufacturing Of High Performance Flexible Thermoelectric Generators Using Nanoparticle Inks, Tony Valayil Varghese

Boise State University Theses and Dissertations

Flexible thermoelectric devices are attractive power sources for the growing demand of flexible electronics and sensors. Thermoelectric generators have an advantage due to no moving parts, silent operation and constant power production with a thermal gradient.

Conventional thermoelectric devices are rigid and fabricated using complex and relatively costly manufacturing processes, presenting a barrier to increase the market share of this technology. To overcome such barriers, this work focuses on developing near ambient-temperature flexible thermoelectric generators using relatively low-cost additive manufacturing processes. A screen printable ink was developed for transforming nanoparticle ink into high-performance flexible thermoelectric generators with a peak thermoelectric ...


Construction Of An Auger Microscope, Charles Soulen May 2019

Construction Of An Auger Microscope, Charles Soulen

Undergraduate Honors Theses

This thesis describes the design, adaptations and characterizations necessary to partially turn an Auger Electron Spectroscopy Instrument (AES) into an Auger Electron Microscope (AEM). The completed AEM will be able to scan and characterize materials over an area, unlike the AES which only took data from a single point. However, due to time constraints, this thesis only partially describes the creation of an AEM. We were able to show proof-of-concept, though, we were unable to run AEM on a material. We have also increased the theoretical accuracy of the instrument by replacing decades-old electronics with modern alternatives. Again, due to ...


A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande May 2019

A Study On Ultrasonic Energy Assisted Metal Processing : Its Correeltion With Microstructure And Properties, And Its Application To Additive Manufacturing., Anagh Deshpande

Electronic Theses and Dissertations

Additive manufacturing or 3d printing is the process of constructing a 3-dimensional object layer-by-layer. This additive approach to manufacturing has enabled fabrication of complex components directly from a computer model (or a CAD model). The process has now matured from its earlier version of being a rapid prototyping tool to a technology that can fabricate service-ready components. Development of low-cost polymer additive manufacturing printers enabled by open source Fused Deposition Modeling (FDM) printers and printers of other technologies like SLA and binder jetting has made polymer additive manufacturing accessible and affordable. But the metal additive manufacturing technologies are still expensive ...


Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi May 2019

Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi

Electronic Theses and Dissertations

Paper coating layers are subject to various stresses and deformations in many converting processes such as calendering, printing, slitting, and folding of the paper. In some cases, products may crack during folding to generate a defect called cracking at the fold (CAF). The parameters that influence these defects are not well understood. The overall goal of this thesis is to better understand the CAF behavior as related to material properties of the coating layer.

A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these ...


Concentration Flow Cells For Efficient Salinity Energy Recovery With Carbonized Peat Moss And Molybdenum Disulfide Electrodes, Haihui Zhu Mar 2019

Concentration Flow Cells For Efficient Salinity Energy Recovery With Carbonized Peat Moss And Molybdenum Disulfide Electrodes, Haihui Zhu

LSU Master's Theses

The globally extractable salinity gradient (SG) energy from the mixing of seawater and river water is estimated to be 3% of worldwide electricity consumption. Here we applied carbonized peat moss (CPM) electrodes and molybdenum disulfide (MoS2) electrodes to a concentration flow cell that is capable of harvesting SG energy based on the electrode (pseudo-)capacitance together with the Donnan potential. The CPM electrodes were made from the visually inexhaustible peat moss by a facile pyrolysis process. With two identical CPM electrodes and a cation-exchange membrane, the cell produced a peak power density of 5.33 W m-2 and ...


Displacement Damage Effects In Gesn Light Emitting Diodes, Kevin K. Choe Mar 2019

Displacement Damage Effects In Gesn Light Emitting Diodes, Kevin K. Choe

Theses and Dissertations

Potential future use on Earth-orbiting satellites calls for investigation into the suitability of GeSn based photonic devices in high energy proton environments. The electroluminescence (EL) intensity of Ge1-xSnx (x = 0, 0.02, 0.069, and 0.094) light emitting diodes was measured before and after irradiation by 2 MeV protons at relatively high fluence levels. The results showed that GeSn devices with higher Sn content were up to 10 times more resistant against proton displacement damage than the pure Ge (x = 0) devices. As Sn concentration increased, the band gap decreased, and V-P hole trap energy level moved further from ...


Characterization Of Metal Contacts On Hydrothermally Synthesized Uranium Dioxide For Novel Semiconductor Applications, Tory E. Robinson Mar 2019

Characterization Of Metal Contacts On Hydrothermally Synthesized Uranium Dioxide For Novel Semiconductor Applications, Tory E. Robinson

Theses and Dissertations

This research is focused on determining which metals or combinations of metals form effective electrical contacts on hydrothermally synthesized UO2 substrates to allow for additional work in characterization of the material as well as the feasibility of its use in semiconductor devices such as solid-state neutron detectors. A methodology was established for selection of candidate metals. Target mixtures composed of Au, Ag, Pt, and Mg were chosen along with several single-metals. Thin metal films were deposited onto tungsten probe tips and hydrothermally synthesized UO2 samples to allow for analysis of mechanical and deposited contact to the substrates through I-V measurements.


Improved Fabrication For Micromirror Arrays, Enoc Flores Mar 2019

Improved Fabrication For Micromirror Arrays, Enoc Flores

Theses and Dissertations

Micromirror devices which consisted of one SU-8 2050 layer, two different exposures, and a series of metal depositions were constructed and evaluated. By varying the exposure, a micromirror structure was fabricated with different thicknesses, a ratio of 1.083 µm/(mJ/cm2) was found. The initial design consisted of four layers. The pillar was made of one SU-8 layer, and the top portion had three layers in the following order: gold, SU-8, and gold. This design could not be released and did not have characteristics of a flat and conformal reflective surface. Several variations of the initial design were explored ...


Scaling Film Cooling Adiabatic Effectiveness With Mass Transfer And Thermal Experimental Techniques, Luke J. Mcnamara Mar 2019

Scaling Film Cooling Adiabatic Effectiveness With Mass Transfer And Thermal Experimental Techniques, Luke J. Mcnamara

Theses and Dissertations

With increasing engine temperatures, it is becoming more important to design effective film cooling schemes. Low temperature, large scale tests are often implemented in the design process to reduce cost and complexity. A nondimensional adiabatic effectiveness can be used as an indication of the performance of a film cooling scheme. However, the coolant flow rate must be properly scaled between the low temperature tests and engine temperatures to accurately predict film cooling effectiveness. This process is complicated by gas property variation with temperature. Tests are commonly conducted using thermal measurement techniques with infrared thermography (IR), but the use of pressure ...


Analysis And Design Of Modular Overhead Protection System Utilizing Readily Available Materials, Zachary J. Spranger Mar 2019

Analysis And Design Of Modular Overhead Protection System Utilizing Readily Available Materials, Zachary J. Spranger

Theses and Dissertations

This research investigated passive overhead protective measures for existing facilities in an urban environment that are vulnerable to enemy munitions fire. A new modular structural system was designed utilizing commercially available construction material consisting of structural tubing, scaffolding clamps, base plates, and simple roofing components. Structural analysis software was used to model nine modular structures to understand the relationship between the load bearing capacity of the structural members and overall dimensions of the system. Environmental variables for the models were set to the Parwan Province in Afghanistan; this region presents worst-case scenarios both for environmental factors and threat of enemy ...


Mechanical Performance Of Structural Systems With Missing Members: From Buildings To Architected Materials, Panagiotis Pantidis Jan 2019

Mechanical Performance Of Structural Systems With Missing Members: From Buildings To Architected Materials, Panagiotis Pantidis

Doctoral Dissertations

Structural systems are potentially subjected to damage initiating scenarios throughout the course of their service time. Depending on the nature and extent of the damaging event, they may experience significant reduction or even complete loss of their mechanical performance. This dissertation delves into the mechanics of structural systems under the notion of missing members from their domain, investigating types of structural systems: a) multi-story steel framed buildings, and b) materials with a truss-lattice microstructure.

Part I of the dissertation investigates the performance of multi-story steel framed buildings under a column removal scenario, developing an analytical framework for their quasi-static robustness ...


Autojack - Hydraulic Powertrain System, Tyce Vu Jan 2019

Autojack - Hydraulic Powertrain System, Tyce Vu

All Undergraduate Projects

A primary problem for mechanics and automotive enthusiasts is the risk associated with lifting and securing a vehicle with conventional jack stands. Often times, improper jack-stand installation results in the vehicle collapsing unexpectedly, causing injury and/or death. This problem can be minimized through the application of a newly re-designed vehicle lifting system. The conventional method for lifting cars is time consuming and can be unsafe in many circumstances. A better, safer, and more efficient lift design was needed; the AutoJack. The approach of the AutoJack design was entirely focused on the safety of lifting a vehicle. Safety was improved ...


Deformation Correlations And Machine Learning: Microstructural Inference And Crystal Plasticity Predictions, Michail Tzimas Jan 2019

Deformation Correlations And Machine Learning: Microstructural Inference And Crystal Plasticity Predictions, Michail Tzimas

Graduate Theses, Dissertations, and Problem Reports

The present thesis makes a connection between spatially resolved strain correlations and material processing history. Such correlations can be used to infer and classify prior deformation history of a sample at various strain levels with the use of Machine Learning approaches. A simple and concrete example of uniaxially compressed crystalline thin films of various sizes, generated by two-dimensional discrete dislocation plasticity simulations is examined. At the nanoscale, thin films exhibit yield-strength size effects with noisy mechanical responses which create an interesting challenge for the application of Machine Learning techniques. Moreover, this thesis demonstrates the prediction of the average mechanical responses ...


Bending Response Of Timber Mortise And Tenon Joints Reinforced With Filler-Modules And Frp Gussets, Andrew Robert Pacifico Jan 2019

Bending Response Of Timber Mortise And Tenon Joints Reinforced With Filler-Modules And Frp Gussets, Andrew Robert Pacifico

Graduate Theses, Dissertations, and Problem Reports

In 2013, the California Bay Area (CBA) passed a set of ordinances to ensure that their 10,000 plus timber soft-story buildings were prepared for seismic events, through nondestructive evaluation methods. Many property owners are searching for an affordable retrofitting system that will also meet CBA’s new laws focusing on installations by the mandated deadlines in 2020. Over the past three to four decades, Fiber Reinforced Polymer (FRP) composites have found their way into the civil infrastructure sector for rehabilitation. The objective of this study is to evaluate the bending behavior retrofitted mortise and tenon timber joints reinforced with ...


Carbon Fiber Monocoque, Dan Brown, Leland Hoffman Jan 2019

Carbon Fiber Monocoque, Dan Brown, Leland Hoffman

Williams Honors College, Honors Research Projects

The University of Akron’s Human Powered Vehicle Team designed a high performing, fully functioning vehicle that is safe, efficient, and practical for the 2018-2019 season. These objectives were the main priorities when it came to the initial stages of designing the vehicle. In addition, the vehicle was designed in accordance with the ASME 2019 Human Powered Vehicle Challenge guidelines to satisfy all the rules and requirements. Additional priorities have been created to teach practical engineering skills and techniques to the students participating in the project through different points in the production process including research, vehicle design, construction, and testing ...


Form Stable Phase-Change Materials, Russell Dent, Marjan Kashfipour, Nitin Mehra, Jiahua Zhu Jan 2019

Form Stable Phase-Change Materials, Russell Dent, Marjan Kashfipour, Nitin Mehra, Jiahua Zhu

Williams Honors College, Honors Research Projects

This work investigates the use of two different polyols, xylitol (Xyl) and erythritol (Ery), in conjunction with boron nitride (BN) aerogels, for the purpose of creating thermally conductive composites. While the BN filler in Xyl composites achieved a high anisotropic thermal conductivity of up to 4.53 W/m-K at 18.2 weight percent filler loading, they do not exhibit good phase-change material qualities due to a low solidification enthalpy even at low cooling rates. Alternatively, the BN-Ery composites have shown promising results with a solidification enthalpy of 225.14 J/g and a melting enthalpy of 385.84 J ...


Benefits Of Aluminum: Comparing The Common Materials In The Bar Grating Industry, Joanthan Geiser Jan 2019

Benefits Of Aluminum: Comparing The Common Materials In The Bar Grating Industry, Joanthan Geiser

Williams Honors College, Honors Research Projects

The main aim of this project is to study the wholistic behavior of the 6xxx series of aluminum for use in the bar grating industry for a waste water treatment environment. This project will study the comparison of certain aluminum 6xxx series alloys to steel, stainless steel, and glass fiber-reinforced plastic. While comparing these materials, it will look at the mechanical properties such as modulus of elasticity, yield strength, and ultimate tensile strength. In addition, the available corrosion test of the 6xxx series aluminum alloys will be examined to find a generalization of the corrosion behavior for this series. A ...


Development Of Functional Biomaterials Using Protein Building Blocks, Li-Sheng Wang Jan 2019

Development Of Functional Biomaterials Using Protein Building Blocks, Li-Sheng Wang

Doctoral Dissertations

Proteins have intrinsic molecular properties that are highly useful for materials applications, especially for biomaterials. My research has focused on translating these molecular properties to materials surface behavior. In one approach, I developed a fluorous-based thermal treatment strategy to generate stable thin films from a variety of naturally abundant proteins. The different surface properties generated from the choice of protein were utilized to modulate cell-surface interactions, prevent bacterial adhesions, and control drug loading/release. I have used nanoimprint lithography to generate patterned protein films for cell alignment. Coupling with inkjet printing deposition, I have fabricated mixed protein films with spatial ...


The Investigation Of Surface Barrier During Molecular Transport In Hierarchical Zeolites, Xiaoduo Qi Jan 2019

The Investigation Of Surface Barrier During Molecular Transport In Hierarchical Zeolites, Xiaoduo Qi

Doctoral Dissertations

Hierarchical zeolites with micropore lengths on the order of nanometers have been synthesized with the aim of reducing mass transfer limitation. However, due to large external surface to volume ratios, the mass transport in these materials can be hindered by a secondary rate limitation step imposed on the external surface of the zeolites. This has led to the general phenomenon referred to as “surface barriers”, which cause the enhancement in mass transport being far lower than expected. In order to fully unlock the potential of hierarchical zeolites, it is imperative to fundamentally understand the molecular transport in these new types ...