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Thermomechanical Process Simulation And Quantification Of Nanoscale Precipitation Influencing Ductility And Strength During Alloy Processing, Alyssa Stubbers

Theses and Dissertations--Chemical and Materials Engineering

Experimental process simulation and quantification of microstructure development during processing are challenging due to limitations with machinery temperature capability, inadequate resolution and sampling volume of currently available characterization techniques, and difficulty characterizing material microstructures as close to processing-relevant conditions as possible. This dissertation addresses how process simulation can be performed using Gleeble thermomechanical technologies and how microstructure development during these processing simulations can be quantified both in-situ and ex-situ.

The first portion of this dissertation demonstrates how Gleeble technologies can be applied to simulate complex material processing conditions in order to produce process-property profiles that can be used to inform …

The Characterization Of Atmospheric Turbulence And Its Effect On Laser Beam Propagation, Michael Cox

All Theses

Having a controlled environment to measure atmospheric turbulence is essential to understanding its effects on different laser beam characteristics. The Clemson Variable Turbulence Generator (VTG) has the capability to propagate a laser beam up to 100 m and be able to dial many turbulence settings up to a heat flux of 357 W/m². A high-speed camera, power detector, and high-resolution temperature probes characterize the VTG with theoretical turbulence spectrums. The exponent associated with the Rayleigh-Bénard (RB) temperature structure constant equation is studied. Two different laser beam profiles are used throughout this work: Gaussian and Asymmetric Perfect Vortex (APV). …

Naphtha Characterization (Piona, Density, Distillation Curve And Sulfur Content): An Origin Comparison, Aline Pioli Silva, Juliana Otavia Bahú, Renato Soccol Jr., Leonardo Rodriguez-Urrego, William Stive Fajardo-Moreno, Hiram Moya, Jeffrey Leon-Pulido, Víktor Oswaldo Cárdenas Concha

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Naphtha is an important distillation product of crude oil, and is used as a raw material for first-generation products such as ethylene, propylene, gasoline, xylene (BTX), and others. However, due to the different sources of crude oil, differences in naphtha composition impact the quality of conversion processes. Parameters such as pressure, charge flow, and temperature need to be adjusted for conversion efficiency. This work aims to compare naphtha samples from different origins, through the analysis of distillation curve (ASTM D86), density (ASTM D4052), total sulfur (ASTM D4294), and n-paraffins, iso-paraffins, olefins, naphthene, and aromatics (PIONA, ASTM D5134). Among these parameters …

In-Situ Characterization Of Surface Quality In Γ-Tial Aerospace Alloy Machining, David Adeniji

Theses and Dissertations--Mechanical Engineering

The functional performance of critical aerospace components such as low-pressure turbine blades is highly dependent on both the material property and machining induced surface integrity. Many resources have been invested in developing novel metallic, ceramic, and composite materials, such as gamma-titanium aluminide (γ-TiAl), capable of improved product and process performance. However, while γ-TiAl is known for its excellent performance in high-temperature operating environments, it lacks the manufacturing science necessary to process them efficiently under manufacturing-specific thermomechanical regimes. Current finish machining efforts have resulted in poor surface integrity of the machined component with defects such as surface cracks, …

Synthesis And Characterization Of Functiona Materials For 3d Printed Composites, Elizabeth Irene Reza

Open Access Theses & Dissertations

The following body of work encompasses the synThesis, upscaling, additive manufacturing, and characterization of microspheres as functional fillers incorporated into polymer syntactic foams. Synthesizing microspheres permits control over morphology, dispersion of particles, and size while the use of direct write manufacturing allowed for the controllability of filler orientation. Two different syntactic foams were developed from similar methodologies: (1) a silicone syntactic foam (2) epoxy syntactic foam. The silicone epoxy foam showed an increasing in damping and elastic modulus. The epoxy syntactic foams showed an enhanced thermal and electrical properties.

Thermal Testing And Characterization Of Nanoparticles Synthesized For Biological Treatment, Tonie Butler

Mechanical Engineering Undergraduate Honors Theses

The overall goal of this research project is to synthesize iron core, silica capped nanoparticles that, when they are exposed to a particular magnetic field, will react by increasing in temperature and emitting substantial thermal output. They will be injected into the human body for biological benefit by targeted thermal radiation. Once in the human body, ideally, they will be able to target a specific area, and then a magnetic field will be applied to induce thermal output through the process of hyperthermia. As the nanoparticles emit heat, they will mimic the natural bodily behavior seen by way of hyperthermia, …

In-Situ Calibrated Modeling Of Residual Stresses Induced In Machining Under Various Cooling And Lubricating Environments, Julius M. Schoop

Mechanical Engineering Faculty Publications

Although many functional characteristics, such as fatigue life and damage resistance depend on residual stresses, there are currently no industrially viable ‘Digital Process Twin’ models (DPTs) capable of efficiently and quickly predicting machining-induced stresses. By leveraging advances in ultra-high-speed in-situ experimental characterization of machining and finishing processes under plane strain (orthogonal/2D) conditions, we have developed a set of physics-based semi-analytical models to predict residual stress evolution in light of the extreme gradients of stress, strain and temperature, which are unique to these thermo-mechanical processes. Initial validation trials of this novel paradigm were carried out in Ti-6Al4V and AISI 4340 alloy …

Neutron Diffraction Study Of Multiferroic 0.6nife2o4/0.4batio3 Composite, Engkir Sukirman, Yosef Sarwanto, Syahfandi Ahda, Andon Insani

Makara Journal of Technology

Neutron diffraction study on the 0.6NiFe2O4/0.4BaTiO3 multiferroic composite has been carried out. The 0.6NiFe2O4/0.4BaTiO3 multiferroic composites have been synthesized by solid reaction method. In this study, 20 g of BaTiO3 (BTO) and 20 g of NiFe2O4 (NFO) compounds were prepared from the powder raw materials of BaO3 and TiO2 for BTO, and NiO and Fe2O3 for NFO. Furthermore, both BTO and NFO were each crushed for 5 hours using High Energy Milling (HEM). Then the BTO and NFO were calcined in the furnace at 950 °C/5 hours and 900 °C/5 hours, respectively. Both NFO and BTO precursors were manually mixed …

Characterization And Optimization Of A Propeller Test Stand, Colin Bruce Leighton Benjamin

Mechanical & Aerospace Engineering Theses & Dissertations

In recent history, there has been a rapid rise in the use of drones, and they are expanding in popularity each year. The widespread use and future capabilities of these unmanned aerial vehicles (UAVs) will call for increased study and classification of propellers to maximize their performance. As a result, it is necessary to have continuity in the development, maximization, and optimization of propeller test stand’s capability to collect accurate and precise measurements. It is of significant advantage to have the capability of accurately characterizing a propeller based on its thrust and torque. In this study, a propeller test stand …

Materials Characterization In The Development Of Combustion-Based Methods For Synthesis Of Niobium Silicides, Edgar Maguregui

Open Access Theses & Dissertations

The use of characterization techniques is essential for a better understanding of novel manufacturing processes and for investigating how the process parameters affect the products. Mechanically activated self-propagating high-temperature synthesis (MASHS) is an attractive method for the production of high-temperature structural materials. In the present work, it was used to fabricate Nb5Si3 compound and Nb5Si3/Nb composites. It has been shown that for mechanical activation of Nb/Si mixtures, a planetary ball mill is more effective than a shaker ball mill used in prior research on MASHS of Nb5Si3. The influence of mixture composition and experimental parameters, such as milling time and …

Improving The Delivered Specific Impulse Of Composite Rocket Propellant Through Alteration Of Chemical Composition: Methodology And Parameters For Characterization Of Propellant And Validation Of Simulation Software Common To The Amateur Rocketry Community, Isaac O'Brien, Austin Ryan

Williams Honors College, Honors Research Projects

In this study, two solid composite rocket propellants were designed utilizing ProPEP, a rocket propellant formulation software common in the amateur and hobby rocketry communities. The two propellants were designed to optimize specific impulse relative to a literature propellant designed by 1020 Research Labs. The literature propellant was also tested in order to validate the design of experiment as well as the mixing and testing procedures. All three propellants, which includes the literature propellant RCS-P, and the two novel propellants AKR-P1 and AKR-P2 were characterized with static tests. The results of the static tests provide data on propellant performance and …

Characterization Of The Surface Condition In Aa6061 Resulting From Deep Rolling As A Function Of Common Industrial Parameters, Andrew Kenneth Layer

Masters Theses

"Roller burnishing is widely used in industry to improve the surface finish and fatigue life of components. As weight reduction continues to grow in the automotive and transportation industries, deep rolling can help maintain product performance by mitigating the increase in component stresses resulting from lower weight systems. Deep rolling parameters such as tool, applied angle, feed rate, spindle speeds, and relative tool direction all affect cycle time, product performance, and appearance. The effects of common industrial parameters on the resultant surface roughness and residual stress profiles were studied in this investigation. The samples were manufactured on a CNC lathe …

Investigation Of Various Factors Affecting Quantification And Characterization Accuracy Of Nox Measurement At Near Zero Level In A Cvs Sampling Set-Up, Samuel Abimbola Ogunfuye

Graduate Theses, Dissertations, and Problem Reports

Accurate measurement of oxides of nitrogen (NOx) concentrations at near-zero levels using the constant volume sampling (CVS) system is a critical consideration in emissions quantification for engine and vehicle research and certification purposes. Various technological efforts and research are being implemented to ensure emissions from automobile and on-road transportation sources tend towards lower concentrations. This development has resulted in NOx concentration measurements to shift towards near-zero and thus, reach the detection limits of traditional measurement approaches and methods. There are several factors that might deter achieving measurement accuracy at this level, as their effect becomes significant at low NOx concentrations. …

Pyrolysis Of Fiber-Plastic Waste Blends, Shreyas Kolapkar

Dissertations, Master's Theses and Master's Reports

The main objective of this work is to investigate fast pyrolysis of fiber and plastic feedstocks in order to understand the synergistic effect from their co-pyrolysis. In this on-going work, fiber, plastic and their blend are characterized and pyrolysis oil is produced from them in the fast batch pyrolysis reactor. Based on a heat transfer model it is shown that results of oil produced from batch reactor will be applicable to the continuous paddle reactor. From feedstock characterization, chlorine was observed particularly in the plastic feedstock. Thus, chlorine removal method using torrefaction and high shear mixing was implemented and was …

Effect Of Poisson’S Ratio On Young's Modulus Characterization Using Ultrasonic Technique By Modeling, Michael Onyetube

Electronic Theses and Dissertations

The past 27 years has witnessed a revolutionary growth in the progress of material development and application in almost all industry and business sectors, and this seems to be continuing even today. So many material-driven innovations have enabled the global spread in technology and improvements in capability, ranging from communications to aerospace and healthcare, to automotive and agriculture. Mechanical behavior of elastic materials is modeled by two main independent constants; Young’s modulus and Poisson’s ratio. An accurate measurement of both constants is necessary in most engineering applications, for example, the standard materials used for the calibration of some equipment, quality …

Characterization Of Evaporation/Condensation During Pool Boiling And Flow Boiling, Mostafa Mobli

Theses and Dissertations

Present dissertation has investigated pool and flow boiling and their characteristics via numerical means. A code was developed to investigate and enhance heat transfer performance during different modes of phase change phenomena. Multiphase heat transfer has proven to be one of the most effective means of heat transfer in different industries, therefore, there have been numerous experimental and numerical studies on the subject of phase change phenomena in a wide range of conditions and setups; yet there are complex bubble dynamics and heat transfer characteristics that remain unresolved. To have a more detailed look at and a better understanding of …

Cyber-Physical System Characterization And Co-Regulation Of A Quadrotor Uas, Seth E. Doebbeling

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

An Unmanned Aircraft System (UAS) is a Cyber-Physical System (CPS) in which a host of real-time computational tasks contending for shared resources must be cooperatively managed to obtain mission objectives. Traditionally, control of the UAS is designed assuming a fixed, high sampling rate in order to maintain reliable performance and margins of stability. But emerging methods challenge this design by dynamically allocating resources to computational tasks, thereby affecting control and mission performance. To apply these emerging strategies, a characterization and understanding of the effects of timing on control and trajectory following performance is required. Going beyond traditional control evaluation techniques, …

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

Thermal Transport In Lithium Ion Batteries: An Experimental Investigation Of Interfaces And Granular Materials, Aalok Jaisheela Uday Gaitonde

Open Access Theses

Increasing usage and recent accidents due to lithium-ion (Li-ion) batteries exploding or catching on fire has inspired research on the characterization and thermal management of these batteries. In cylindrical 18650 cells, heat generated during the battery's charge/discharge cycle is poorly dissipated to the surrounding through its metallic case due to the poor thermal conductivity of the jelly roll, which is spirally wound with many interfaces between electrodes and the polymeric separator. This work presents a technique to measure the thermal conduction across the metallic case-plastic separator interface, which ultimately limits heat transfer out of the jelly roll.

The polymeric separator …

In-Situ Particle Sizing Of Agglomerates In Aluminized Solid Composite Propellants Using Digital Inline Holography (Dih), Michael S. Powell

Open Access Theses

Aluminized ammonium perchlorate composite propellants (APCP) form large molten agglomerated particles that can result in poor combustion performance and increased two-phase flow losses. Quantifying agglomerate size distributions is important for assessing these losses for different types of aluminum fuels that can help improve rocket performance. It is highly desirable to measure particle sizes in-situ using non-intrusive optical methods, rather than conventional particle collection, which can have large uncertainties. Regular high-speed microscopic imaging suffers from a limited depth of field. Digital inline holography (DIH) is an alternative approach that results in 3D information through numerical reconstruction. In this paper, DIH approach …

Thermodynamic And Compositional Assessment Of Q-Phase In Al–Si–Mg–Cu Alloys Using 3dapt And In-Situ Tem, Andrew Bobel, Weiwei Zhang, Nick Hatcher, Qigue Wang, Mike Walker, Greg Olson

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Data Driven Low-Bandwidth Intelligent Control Of A Jet Engine Combustor, Nathan L. Toner

Open Access Dissertations

This thesis introduces a low-bandwidth control architecture for navigating the input space of an un-modeled combustor system between desired operating conditions while avoiding regions of instability and blow-out. An experimental procedure is discussed for identifying regions of instability and gathering sufficient data to build a data-driven model of the system's operating modes. Regions of instability and blow-out are identified experimentally and a data-driven operating point classifier is designed. This classifier acts as a map of the operating space of the combustor, indicating regions in which the flame is in a "good" or "bad" operating mode. A data-driven predictor is also …

Characterization Of Pool Boiling Heat Transfer From Porous-Coating-Enhanced Surfaces, Suchismita Sarangi

Open Access Dissertations

Development of techniques for enhancement and optimization of thermal management technologies has been a highly active area of research in recent decades in response to the rapid emergence of compact, high-power electronic systems. Immersion cooling by boiling is one of the preferred methods for high power density applications, due to its passive nature and high heat transfer coefficients obtained. Pool boiling heat transfer has been extensively studied in recent decades to understand the inherent mechanisms yielding the high heat transfer rates, as well as to further enhance the heat transfer by simple modifications or additions to existing approaches. This thesis …

Theory, Fabrication, And Experimentation Of Phononic Crystals In Mems At Micro/Nano Scale: Engineering Of Thermal And Rf Phonons To Applications In Thermoelectrics And Microresonators, Seyedhamidreza Alaie

Mechanical Engineering ETDs

Phononic Crystals (PnCs) are novel materials comprised of a periodic structure of inclusions in a matrix. This periodic arrangement creates phononic bandgaps, and modifies phononic bandstructures of a material. Such a property offers promising applications at the micro and nano scales to engineer acoustic filters, high Q-factor resonators, and thermoelectric properties of materials. Studying PnCs at the micro/nano scale requires specific characterization techniques, which rely on Micro Electro Mechanical Structures (MEMS). This work focuses on the study, and characterization of PnCs using MEMS in view of their prospective applications in thermoelectric materials, microresonators and acoustic filters, and also the prospective …

Manufacturing And Characterization Of Energetic Materials, Carlos Alberto Catzin

Open Access Theses & Dissertations

Few products take several years of research effort to be synthesize yet disintegrate in scarcely millionths of a second when used. Despite their short lifespan energetic materials, particularly high explosives, are in demand as never before by the Aerospace, Defense, Energy, Gas, Mining, and Oil Industry for their unique properties. One class of high explosives known as polymer bonded explosives (PBXs) are popularly used in a wide variety of applications ranging from solid rocket propellants to the main explosive charge in conventional ammunitions. A key characteristic behind the popularity of PBXs in comparison to other high explosives is their handling …

A Method For The Characterization And Selection Of Compliant Joints, Ronald George Saleeby

All Theses

A compliant joint is a connection between two bodies that derives its movement from the deflection of flexible members rather than rigid connections, like traditional joints. Compliant joints have potential advantages that include longer part life, reduction of parts in assemblies, and reduced wear. Traditional compliant mechanism design methodologies have limitations involving the burden of necessary knowledge required to satisfactorily use them. The method presented in this thesis was developed to provide compliant joint design solutions independent of the traditional methods of compliant joint design by allowing the selection of compliant joints from a repository. The repository is populated by …

Synthesis, Characterization, And Electrochemical Properties Of Polyaniline Thin Films, Soukaina Rami

USF Tampa Graduate Theses and Dissertations

Conjugated polymers have been used in various applications (battery, supercapacitor, electromagnetic shielding, chemical sensor, biosensor, nanocomposite, light-emitting-diode, electrochromic display etc.) due to their excellent conductivity, electrochemical and optical properties, and low cost. Polyaniline has attracted the researchers from all disciplines of science, engineering, and industry due to its redox properties, environmental stability, conductivity, and optical properties. Moreover, it is a polymer with fast electroactive switching and reversible properties displayed at low potential, which is an important feature in many applications. The thin oriented polyaniline films have been fabricated using self-assembly, Langmuir-Blodgett, in-situ self-assembly, layer-by-layer, and electrochemical technique. The focus of …

Functionalization Of Amorphous Carbon Nanotubes For Au Nanoparticles Hybridization

Faculty of Engineering University of Malaya

Our study focuses on selection of nitric acid, sulfuric acid, citric acid, and hydrochloric acid as the most suitable oxidation agent for a-CNT. Nitric acid functionalized a-CNT has the highest value of zeta potential -142.9 mV, followed by H2SO4, citric acids, and HCl functionalized samples of -60.3 mV, -15.9 mV, and -3.2 mV, respectively. High values of zeta potential represents surface charges, which refers to carboxyl groups present on tubes' bodies. At the same time, auric chloride (AuCl3) solution treatment was applied on citric acid, nitric acid, hydrochloric acid, and sulfuric acid treated a-CNT at the same condition. Nitric acid …

Material Characterization And The Effects Of Moisture And Drying On Injection Molded Torlon 5030, Michael R. Di Re

Master's Theses

The effects of water absorption and drying were studied on injection molded Torlon 5030, a high performance thermoplastic fabricated by Solvay Specialty Polymers. Torlon 5030 contains 30% by weight glass fibers in a polyamide-imide base resin. The objective behind this work was to test and better define relevant properties for industrial applications using this material. While the material design guide offers information on many mechanical properties including tensile, fatigue, and creep data; there is little to no publicly published data on the effects of water absorption and any subsequent drying of Torlon 5030. Blistering was also studied. With exposure to …

High Capacity Lithium-Ion Battery Characterization For Vehicular Applications, Sazzad Hossain Ahmed

Masters Theses

A lithium-ion battery is one of the key research topics in energy storage technologies. Major characterization tests such as static capacity, open circuit voltage (OCV), hybrid pulse power characterization (HPPC) have been conducted on two different chemistries, LiMnNi and LiFePO₄, high capacity lithium-ion batteries over a wide range of temperatures from 50ºC to -30ºC. Detail analysis of temperature effects on battery capacity and simple models of direct current resistance (DCR) increment and power decrement over temperatures have been proposed using the test results. Electrochemical impedance spectroscopy (EIS) tests have been performed to find out the dominant internal resistances …