Engineering Commons^™

Performance Qualification And Raman Investigation On Cell Behavior And Aging Of Lifepo₄ Cathodes In Lithium-Ion Batteries, Amir Salehi

Material Science and Engineering Theses - Archive

This thesis explores the ability of Raman spectroscopy to understand the complex chemistry taking place in LiFePO₄ cathodes of Li ion batteries. The performance of Li ion batteries was optimized through electrode fabrication and assembling procedures. Various amounts of Timcal Super P carbon were used to construct a conductive network of C-LiFePO₄ particles and the performance of the cathodes was examined during battery cycling. Raman spectroscopy along with electrochemical characterization such as charge/ discharge curves, electrochemical impedance spectroscopy and Cyclic Voltammetry was employed for detailed investigation of battery performance and aging. It is found that both quantity and quality of …

Effects Of Surface Plasmon Excitations On Photoluminescence By Cdse/Zns Quantum Dots, Ankit Kumar Singh

Material Science and Engineering Theses - Archive

The influence of localized surface plasmons (LSPs) and surface plasmon polaritons (SPPs) on the photoluminescence (PL) spectra of core/shell type CdSe/ZnS quantum dots (QDs) has been studied. Thin film samples of these QDs were deposited on glass slides, irradiated by 514 nm polarized beam from an Argon-ion laser, and PL spectra were measured using a high-resolution 1250M JY-Horiba spectrometer equipped with liquid-nitrogen cooled CCD detector. In the first set of experiments, PL spectra were measured on QDs and QDs-Au NPs mixture as a functions of the intensity of the 514 nm laser beam. In the second set of experiments, PL …

Synthesis Of Silver-Diamond Like Carbon Thin Films By Magnetron Sputtering, Venkatesh Majji

Material Science and Engineering Theses - Archive

Diamond-like carbon thin films are been used in wide range of applications due to their attractive tribological properties. Metal-doped DLC films have significant properties which make them compatible to use in larger variety of applications. The present study examines the dispersion and their effect on various tribological properties when Ag is incorporated into the DLC thin films. These Ag-DLC nanocomposite films were synthesized by a hybrid CVD and magnetron sputtering process in a discharge composed of CH4, and Ar atmosphere. These DLC and Ag-DLC films were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy …

Role Of Engine Age And Lubricant Chemistry On The Characteristics Of Egr Soot, Olusanmi Adeniji Adeniran

Material Science and Engineering Theses - Archive

Exhaust products of Diesel Engines serves as an environmental hazard, and to curtail this problem a Tier 3 emission standard was introduced which involves change in engine designs and introduction of EGR systems in Diesel engines. EGR systems, however has the challenge of generating soot which are abrasive and are major causes of wear in Diesel engines. This work has studied the characteristics of EGR soot formed in different range of engine age and in different lubricant chemistries of Mineral and Synthetic based diesel Oils. It is found that lubricant degradation is encouraged by less efficient combustion as engine age …

Cold Plasma Treatment Of Magnetic Nanoparticles, Ke Wang

Material Science and Engineering Theses - Archive

This thesis investigates the application of cold plasma to remove the oleic acid bonded on magnetic nanoparticles: SmCo5 nanoflakes prepared via surfactant assisted high energy ball milling and CoFe2O4 nanoparticles prepared via chemical synthesis. Oleic acid molecules bonded on nanoparticles are in the carboxylate form which could not be washed away by organic solvents in ultrasonic bath; only free oleic acid molecules left on the nanoparticle surface after ball milling can be washed away through ultrasonic bath. High temperature annealing method works for removing oleic acid but nanoparticles would be damaged because of oxidation and decomposition.The RF cold plasma has …

Compaction Physics Of Solid Additive Blends : A Thermal Properties Study, Amy Brown

Material Science and Engineering Theses - Archive

Compacted solid additive blends have attracted the interest of the polymers industry due to their ability to improve processability. However, limited research has been performed to analyze the thermal properties that these additives have during pelletization.This research studies the reaction behavior of erucamide and silica, when in a pure and mixed form, with each other when thermal conductivity and frictional heating experiments are conducted. During the thermal conductivity study, it was found that pure erucamide had a thermal conductivity of 0.37 W/mK. The thermal conductivity of pure silica could not be found since silica will not compact to itself. Therefore, …

Synthesis And Characterization Of Transition Metal Arsenide Nanocrystals And The Metastability And Magneto-Structural Phase Transition Behavior Of Mnas Nanocrystals, Yanhua Zhang

Wayne State University Dissertations

This dissertation study focuses on (1) probing the magneto-structural phase transformation in nanoscale MnAs; (2) evaluation of the size-dependent phase stability of type-B MnAs (prepared by rapid injection); and (3) developing a general synthetic method for transition metal arsenide nanoparticles.

Discrete MnAs nanoparticles that adopt different structures at room temperature (type-A, α-structure and type-B, β-structure) have been prepared by the solution-phase arrested precipitation method. Atomic pair distribution and Rietveld refinement were employed on synchrotron data to explore the structural transitions of the bulk and nanoparticle samples, and these results were compared to AC magnetic susceptibility measurements of the samples. The …

Fabrication And Characterization Of Single Electron Device And Study Of Energy Filtering In Single Electron Transport, Liang-Chieh Ma

Material Science and Engineering Dissertations - Archive

Single electron devices, in which transport of single electrons is precisely controlled, hold a great promise as important components of future electronic devices and sensors. However, technical challenges have prevented their implementations to practical electronic and sensing systems. First of all, the fabrication of single electron devices requires their components to be defined and arranged in nanoscale precision, a great challenge for a large-scale fabrication. Secondly, for room temperature operation, the single-electron charging energy should be much larger than the room-temperature thermal energy, ~25 meV, requiring use of extremely small Coulomb island, which is difficult to control. This has limited …

Corrosion And Hydrogen Embrittlement Of Nanocrystalline Nickel, Tapas Desai

Material Science and Engineering Theses - Archive

Nanocrystalline (nc) materials have attracted the interest of the scientific community because of their unique physical and mechanical properties. However, limited research has been performed to analyze their electrochemical behavior. The majority of research in the field of electrochemical and corrosion behavior exists for electrodeposited nanocrystalline metals.This research studies the behavior of sputter-deposited nc Nickel films in corrosive and hydrogen environment by potentiodynamic polarization and microindentation. The surface morphology and composition of the samples was examined by Scanning Electron Microscopy and Energy Dispersive X-Ray spectroscopy. Bulk Ni samples exhibit mild passivation in 3.5 % NaCl solution. The surface reveals a …

X-Ray Scattering Investigations Of Metallic Thin Films, Andrew Warren

Electronic Theses and Dissertations

Nanometric thin films are used widely throughout various industries and for various applications. Metallic thin films, specifically, are relied upon extensively in the microelectronics industry, among others. For example, alloy thin films are being investigated for CMOS applications, tungsten films find uses as contacts and diffusion barriers, and copper is used often as interconnect material. Appropriate metrology methods must therefore be used to characterize the physical properties of these films. Xray scattering experiments are well suited for the investigation of nano-scaled systems, and are the focus of this doctoral dissertation. Emphasis is placed on (1) phase identification of polycrystalline thin …

Development And Characterization Of Nanoparticlee Enhancements In Pyrolysis-Derived High Temperature Composites, James Mckee

Electronic Theses and Dissertations

Thermal protection systems, which are commonly used to protect spacecraft during atmospheric entry, have traditionally been made of materials which are traditionally high in manufacturing costs for both the materials needed and the manufacturing complexity, such as carbon-carbon composites and aerogels. [1] In addition to their manufacturing costs, these materials are also limited in their strength, such as PICA, in a way that necessitate the use of tiles as opposed to single structures because they are not capable of supporting larger structures. [2] The limitations of polymer reinforced composites have limited their entry into these applications, except for pyrolyzed composite …

Development Of Polymer Derived Sialcn Ceramic And Its Applications For High-Temperature Sensors, Gang Shao

Electronic Theses and Dissertations

Polymer-derived ceramic (PDC) is the name for a class of materials synthesized by thermal decomposition of polymeric precursors which excellent thermomechanical properties, such as high thermal stability, high oxidation/corrosion resistance and high temperature multifunctionalities. Direct polymer-to-ceramic processing routes of PDCs allow easier fabrication into various components/devices with complex shapes/structures. Due to these unique properties, PDCs are considered as promising candidates for making high-temperature sensors for harsh environment applications, including high temperatures, high stress, corrosive species and/or radiation. The SiAlCN ceramics were synthesized using the liquid precursor of polysilazane (HTT1800) and aluminum-sec-tri-butoxide (ASB) as starting materials and dicumyl peroxide (DP) as …

Barium Based Halide Scintillator Ceramics For Gamma Ray Detection, William Shoulders

Electronic Theses and Dissertations

As our understanding of ceramic processing methods for the purpose of fabricating polycrystalline optical materials has increased over the past few decades, the race is on to bring ceramic technology to markets where single crystalline materials have traditionally been used. One such market is scintillators. This Master’s thesis focuses specifically on a class of materials attractive for use as gamma-ray scintillators. These barium based halides can potentially be utilized in applications ranging from ionizing radiation detection in the field to high-energy physics experimentation. Barium bromide iodide and barium chloride single crystals have already showed high light yield, fast scintillation decay, …

Self-Assembled Two-Component Organic Tubes: Structures And Applications, Wenlang Liang

Electronic Theses and Dissertations

Bile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into the intestines. They play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsifications. The amphipathic and chiral nature of bile acids makes their unique building blocks for assembling supramolecular structures including vesicles, fibers, ribbons and hollow tubes. Lithocholic acid (LCA) is a secondary bile acid. Our studies show LCA can selfassemble into helical tubes in aqueous solution by the linear aggregation and fusion of vesicles. The objective of this dissertation is to …

Engineering Nanoparticle And Nanoring Patterns For The Study Of Molecular Crystallization Under Nanoconfinement, Sunxi Wang

Wayne State University Dissertations

This dissertation focuses on generating the inorganic nanoparticle/organic nanorod hybrid nanostructures by the strategy of nanoparticle induced molecular crystallization developed by us and the new electrochemical method. We synthesize the gold nanoparticles with different sizes and functional groups and then fabricate the nanohybrids with fatty acid nanorods by spin coating method. Atomic force microscope monitors the topography of the hybrid nanostructures to help understand the underlying mechanism of the crystallization process. This successful self-assembled method could be used to fabricate nanohybrids based on seed-mediated nucleation. Also the novel "nano-flasks" have been generated by particle lithography method, which could be served …

Diagnosis Of Systemic Inflammation Using Transendothelial Electrical Resistance And Low-Temperature Co-Fired Ceramic Materials, William L. Mercke

Theses and Dissertations--Chemical and Materials Engineering

Systemic inflammation involves a complex array of cytokines that can result in organ dysfunction. Mortality remains high despite the vast amount of research conducted to find an effective biomarker. The cause of systemic inflammation can be broad and non-specific; therefore, this research investigates using transendothelial electrical resistance (TEER) measurements to better define systemic inflammatory response syndrome (SIRS)/sepsis within a patient. Results show a difference in TEER measurements between healthy individuals and SIRS-rated patients. This research also displays correlations between TEER measurements and biomarkers currently studied with systemic inflammation (tumor necrosis factor-α, C- reactive protein, procalcitonin). Furthermore, this research also presents …

Interdiffusion Study Of Mg-Aa6061 System, Mian Fu

Electronic Theses and Dissertations

Magnesium (Mg) is a light-weight metal that has extraordinary physical and chemical properties for many potential applications in automobile, military, and electronics. Aluminum alloys, because of its light-weight, high strength and corrosion resistance have a wide range of commercial applications. Given these two, sometime competing, alloy systems, there are now many applications where the metallurgical compatibility of Mg- and Al-alloys are required for engineering applications. One such case is the development of diffusion barrier for U-Mo metallic fuel in Al-alloy cladding, where Mg, with its complete immiscibility with U and Mo is being considered as the diffusion barrier. While negligible …

The Effect Of Microstructure On The Dynamic Equi-Biaxial Fatigue Behaviour Of Magnetorheological Elastomers, Yanfen Zhou, Stephen Jerrams, Tony Betts, Lin Chen

Conference Papers

Dynamic equi-biaxial fatigue behaviour of isotropic and anisotropic magnetorheological elas-tomers (MREs) based on a silicone rubber matrix was investigated using the bubble inflation method. Con-stant engineering stress amplitude was used as the control mode and samples were fatigued over different stress ranges between 0.75MPa and 1.4MPa. S-N (Wöhler) curves showing plots of stress amplitude (σa) ver-sus cycles to failure (N) are presented. Stress-strain behaviour throughout the fatigue process is described. Elastic modulus (E*) was studied for the specific cycles measured. It was found that anisotropic MREs exhi-bited greater fatigue resistance than isotropic MREs for a given magnetic particle content. Stress …

Examining The Effects Of Computational Tools On Students' Conceptual Understanding Of Thermodynamics Of Material Concepts And Representations, Oyindamola Oluwatimi

Open Access Theses

Technology is becoming a more critical agent for supporting learning as well as research in science and engineering. In particular, technology-based tools in the form of simulations and virtual environments support learning using mathematical models and computational methods. The purpose of this research is to: (a) measure the value added in conveying Thermodynamics of materials concepts with a blended learning environment using computational simulation tools with lectures; and (b) characterize students' use of representational forms to convey their conceptual understanding of core concepts within a learning environment that blended Gibbs computational resource and traditional lectures.

A mix-method approach was implemented …

Prediction Of The Thermomechanical Behavior Of Particle-Reinforced Metal Matrix Composites, Yi Hua, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this paper was to predict the thermomechanical behavior of 2080 aluminum alloy reinforced with SiC particles using the Mori–Tanaka theory combined with the finite element method. The influences of particle volume fraction, stiffness, aspect ratio and orientation were examined in terms of effective Young’s modulus, Poisson’s ratio and coefficient of thermal expansion (CTE) of the composite. The microstructure induced local stress and strain field was obtained through the numerical models of the representative volume element. Results suggested that particle volume fraction had significant impact on the effective Young’s modulus, Poisson’s ratio and CTE of the composite. Stiffer …

Novel Approach Of Using Polyvinylidene Fluoride Langmuir-Schaefer Film On Graphene-Polyaniline Nanocomposite For Supercapacitor Applications, Venkata Priyanka Bolisetty

USF Tampa Graduate Theses and Dissertations

Supercapacitors are well known for their improvised power density compared to batteries. Ongoing research is mainly focused on improving the energy density of supercapacitors by using different electrode material nanocomposites. The recent research has revealed that graphene (G)-polyaniline (PANI) nanocomposite could be a promising material for supercapacitor applications. The supercapacitor is also associated with self-leakage current regardless of any electrode material. The main objectives of the project are to: (i) synthesize highly fabricate supercapacitor based of G-PANI electrode; (ii) improve the energy density of supercapacitor by applying ultrathin monolayer/monolayers film electrode surface. It is crucial to either improve or retain …

Thermal Infrared Reflective Metal Oxide Sol-Gel Coatings For Carbon Fiber Reinforced Composite Structures, Brandon Demar Richard

USF Tampa Graduate Theses and Dissertations

Recent trends in composite research include the development of structural materials with multiple functionalities. In new studies, novel materials are being designed, developed, modified, and implemented into composite designs. Typically, an increase in functionality requires additional material phases within one system. The presence of excessive phases can result in deterioration of individual or overall properties. True multi-functional materials must maintain all properties at or above the minimum operating limit. In this project, samples of antimony and cobalt-doped tin oxide (ATO(Co2O3)) sol-gel solutions are used to coat carbon fibers and are heat treated at a temperature range of 200 - 500 …

Ion Beam Modification Of Single Crystal Sapphire For High Temperature Optical Waveguiding, William Spratt

Legacy Theses & Dissertations (2009 - 2024)

High temperature environments (>1000°C) provide a significant challenge for fiber optic based sensing due to the poor physical properties of silica fiber at elevated temperature. Not only does silica soften above 1000°C, but the dopants that are responsible for the refractive index change between the core and cladding diffuse, reducing the fibers effectiveness as a waveguide. Single-crystal sapphire fiber has the potential to supplement fiber sensing at high temperature however sapphire fiber is unclad and no cladding methods exist that withstand high temperatures. In addition to higher losses the lack of a cladding also leads to decreased sensitivity due …

Ion Beam Nano-Engineering Of Erbium Doped Silicon For Enhanced Light Emission At 1.54 Microns, Sebastian Naczas

Legacy Theses & Dissertations (2009 - 2024)

Erbium doped silicon is of great interest as a potential light source in Silicon Photonics research due to its light emission at 1.54 μm, which corresponds to the minimal loss of optical transmission in silica fibers for telecommunications. In this thesis a basic mechanism for excitation and de-excitation of Er in Si is reviewed. Based on such fundamental understanding, an innovative approach is proposed and implemented to improve Er luminescence properties through the formation of metal nanoparticles via impurity gettering in Si nanocavities.

Microfluidic-Assisted Atomic Force Microscopy For The Mechanical Characterization Of Soft Biological Materials, Aaron Peter Mosier

Legacy Theses & Dissertations (2009 - 2024)

Viable methods for bacterial biofilm remediation require a fundamental understanding of biofilm mechanical properties and their dependence on dynamic environmental conditions. Mechanical test data, quantifying elasticity or adhesion, may be used to perform physical modeling of biofilm behavior, thus enabling the development of novel remediation strategies. To achieve real-time, dynamic measurements of these properties, a novel analysis platform consisting of a microfluidic flowcell device has been designed and fabricated for in situ analysis using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The flowcell consists of microfluidic channels for biofilm establishment that are then converted into an open …

Impacts Of Ion Irradiation On Hfo2-Based Resistive Random Access Memory Devices, Xiaoli He

Legacy Theses & Dissertations (2009 - 2024)

The impacts of ion irradiation on so-called vacancy-change mechanism (VCM) and electrochemical-metallization mechanism (ECM) ReRAM devices based on HfO₂ are investigated using various ion sources: H+ (1 MeV), He+ (1 MeV), N+ (1MeV), Ne+ (1.6 MeV) and Ar+ (2.75 MeV) over a range of total doses (105 - 1011 rad(Si)) and fluences (1012 - 1015 cm-2). VCM-ReRAM devices show robust resistive switching function after all irradiation experiments. VCM resistive switching parameters including set voltage (V_set), reset voltage (V_reset), on-state resistance (R_on) and off-state resistance (R_off) exhibited, in most cases, modest changes …

Understanding Defect Interactions In Si Ultra-Shallow P-N Junctions Formed By Very Low Energy Boron Implantation, Lakshmanan H. Vanamurthy

Legacy Theses & Dissertations (2009 - 2024)

One of the biggest challenges in the scaling of CMOS devices is the formation of a highly activated, abrupt, defect free Source drain extension (SDE) region. This is especially difficult with p-FET's because of the (1) Boron diffusion co-efficient enhancement from Transient enhanced diffusion (TED) and (2) low solid solubility of

The Effect Of Nanostructure On The Electrical Properties Of Metal Oxide Materials, Philip Zachary Rice

Legacy Theses & Dissertations (2009 - 2024)

Resistive random access memory (ReRAM) is a potential replacement technology for Flash and other memory implementations. Advantages of ReRAM include increased scalability, low power operation, and compatibility with silicon semiconductor manufacturing. Most of the ReRAM devices described to date have utilized thin film based metal oxide dielectrics as a resistive switching matrix. The goal of this dissertation project has been to investigate the resistive switching behavior of nanoparticulate metal oxides and to develop methods to utilize these materials in ReRAM device fabrication. To this end, nanoparticles of TiO₂ and HfO₂ were synthesized under a variety of conditions resulting …

The Effect Of Energy Deposition On Pattern Resolution In Electron Beam Lithography, Ananthan Raghunathan

Legacy Theses & Dissertations (2009 - 2024)

Electron beam lithography is one of the most important tools for nanofabrication. Electron beam lithography has consistently been able to offer higher resolution, typically better than 10 nm or so, compared to other techniques. In this work the contribution of electron-substrate interaction to pattern resolution is investigated.

Plasma-Enhanced Atomic Layer Deposition Of Ruthenium-Titanium Nitride Mixed-Phase Layers For Direct-Plate Liner And Copper Diffusion Barrier Applications, Adam James Gildea

Legacy Theses & Dissertations (2009 - 2024)

Current interconnect networks in semiconductor processing utilize a sputtered TaN diffusion barrier, Ta liner, and Cu seed to improve the adhesion, microstructure, and electromigration resistance of electrochemically deposited copper that fills interconnect wires and vias. However, as wire/via widths shrink due to device scaling, it becomes increasingly difficult to have the volume of a wire/via be occupied with ECD Cu which increases line resistance and increases the delay in signal propagation in IC chips. A single layer that could serve the purpose of a Cu diffusion barrier and ECD Cu adhesion promoter could allow ECD Cu to occupy a larger …