Engineering Commons^™

Understanding Failure Mechanisms Using Multi-Scale Analyses To Improve The Performance Of Zinc Metal And Lithium-Ion Batteries, Brendan E. Hawkins

Dissertations and Theses

We are beginning a global transition away from the use of fossil fuels for our energy needs toward using renewable energy sources in order to mitigate the effects of climate change. One of the biggest challenges to this transition is that, unlike fossil fuels, renewable energy systems have inherent intermittency and require supporting energy storage systems to enable reliable power distribution and electrified transportation. Rechargeable batteries are an attractive energy storage option because of their high energy efficiency, versatility, modularity, and ease of use. Lithium-ion batteries (LIBs) have dominated the rechargeable battery market for portable electronics for the past two …

Shear Thickening In Dense Bidisperse Suspensions By Dynamic Simulation, Nelya Malbranche

Dissertations and Theses

Shear thickening, which corresponds to an increase of viscosity with shear rate, is ubiquitously observed in many concentrated suspensions and, as such, has implications for many industrial materials and geological phenomena. Controlling shear thickening is of significant importance, and many studies have been devoted to it. Recent works link shear thickening to the shear-induced transition from a lubricated particle interaction at low shear stress to a predominantly frictional interaction at high stress. In this dissertation, we investigate bidispersity and focus on mechanisms contributing to the viscosity evolution in rate-dependent suspensions, something that has not been addressed before. We perform detailed …

Investigation Of Reactions Occurring In Municipal Solid Waste Residues, Tasnuva T. Moutushi

Dissertations and Theses

Each year more than 290 million tons of municipal solid waste (MSW) is generated in the U.S. Understanding the reactions occurring in waste during disposal, transport, and storage is important to move towards an integrated waste management strategy. Recently some landfills in the U.S. have been reported to exceed the regulatory temperature range, causing numerous regulatory challenges. The reason for this phenomenon is still unidentified. In addition, the co-disposal of the MSW ash in landfills lead to various reactions which can impact the landfill environment. Understanding the reactions occurring in the MSW and in ash is essential to minimize and …

Investigation Of Recyclable And Renewable Crude Oil From Biomass And Plastics, Golam Chowdhury

Dissertations and Theses

In the present world, the nonrenewable source of petroleum crude oil is suspected to cause irreversible climate impacts. So, refinery companies are looking for renewable and recyclable crude oil (RCOs). Biomass and Plastics are a great sources of RCOs. The goal of this work is to design, build and operate a pyrolysis reactor which is capable of converting different solid feedstock derived from waste to pyrolysis oil. The oils are characterized by GC-MS and sent to BASF Corporation in Iselin, NJ for catalytic upgrading potential. In this study, the feedstock ranged from virgin plastic resins (LDPE, HDPE, PS, PP), recycled …

Understanding And Controlling Failure Mechanisms Of The Zinc Anode For Rechargeable Alkaline Batteries, Michael J. D'Ambrose

Dissertations and Theses

In the coming years, the transformation of the electric grid will be in part enabled by safe, low-cost, and reliable large-scale rechargeable battery energy storage systems. Zinc (Zn) alkaline electrodes hold great importance and promise in the battery technology community as they satisfy the safety and cost requirements, yet their behavior in real world application is still poorly understood.

Two experimental studies were carried out, the first of which investigates failure mechanisms and material evolution during cycling of 27 zinc-manganese dioxide (Zn-MnO₂) cells in 37 wt% potassium hydroxide (KOH) electrolyte wherein the percent utilization of the theoretical capacity …

Fundamentals Of Microgel Flooding And Nanoparticles-Stabilized Foams In Enhanced Oil Recovery, Shuaijun Li

Dissertations and Theses

For centuries oil has remained a critical energy source for human civilization. After years of extraction, many oil fields have reached or are reaching a decline stage of production, even though up to a half of the total crude oil reserves in these fields has not been recovered yet. One reason is due to the structural heterogeneity of the oil reservoirs—reservoirs may consist of regions of higher permeability with larger pore size and regions of lower permeability with smaller pore size. Displacing fluids tend to flow through large permeability zones only without reaching the oil trapped in low permeability region; …

Droplets In An Electric Field: Surface Rheology, Coalescence And Rebound, Yu Han

Dissertations and Theses

Electrocoalescence is the process in which pairs of conducting droplets suspended in a continuous dielectric (nonconducting) liquid phase are drawn together and merge upon the application of an electric field. The electric field polarizes each of the droplets in the field direction. The polarization causes the drops to deform and drives a dipolar attraction which forces them to approach each other and coalesce. Many technologies use electric fields to manipulate fluid dispersions. Electrocoalescence is an essential unit operation for separating water droplets in a crude oil. This water in oil emulsion is stabilized by surfactants, such as asphaltenes, resins and …

Molecular-Level Understanding Of Ionic & Electronic Charge Storage Mechanisms In Rechargeable Aluminum Batteries Using Sold-State Nmr, Ankur Lahanu Jadhav

Dissertations and Theses

Rechargeable aluminum-ion batteries are safe and low-cost alternatives to traditional lithium-ion batteries due to the high volumetric capacity (8040 mAh/cm³) of aluminum. However, very few electrode materials have shown reversible aluminum ion intercalation. Intercalation Al³⁺ ions in these structures leads to poor capacity retention, mainly due to slow solid-state diffusion of the highly charged tri-valent aluminum ions within these crystalline structures. In 2015, aluminum ions were shown to reversibly intercalate/de-intercalate into the Chevrel Mo₆S₈ phase, though the intercalation mechanism is not well understood. Alternatively, molecular chloroaluminate ions within the ionic liquid electrolyte have also …

Investigating The Effect Of Electrolyte Concentration And Charging Protocol On Materials Utilization In Rechargeable Zinc Manganese Dioxide Batteries, Snehal H. Kolhekar

Dissertations and Theses

Achieving a highly cyclable, high energy density battery with MnO₂ cathodes encounters many obstacles. Chief among these is the inability of the widely-used γ-MnO₂ polymorph to retain its structural integrity when cycled to near full one-electron discharge capacity, which is about 280mAh/g for commercially available electrolytic manganese dioxide (EMD). In this one-electron range, discharge occurs by proton insertion producing Mn⁺³ which then reverts to γ-MnO₂ on charging. In the first part of the thesis, we investigate the root cause of failure of MnO₂ cathodes under deep cycling in the one-electron discharge range and establish a …

A New Mathematical Theory For The Dynamics Of Large Tumor Populations, A Potential Mechanism For Cancer Dormancy & Recurrence And Experimental Observation Of Melanoma Progression In Zebrafish, Adeyinka A. Lesi

Dissertations and Theses

Cancer, a family of over a hundred disease varieties, results in 600,000 deaths in the U.S. alone. Yet, improvements in imaging technology to detect disease earlier, pharmaceutical developments to shrink or eliminate tumors, and modeling of biological interactions to guide treatment have prevented millions of deaths. Cancer patients with initially similar disease can experience vastly different outcomes, including sustained recovery, refractory disease or, remarkably, recurrence years after apparently successful treatment. The current understanding of such recurrences is that they depend on the random occurrence of critical mutations. Clearly, these biological changes appear to be sufficient for recurrence, but are they …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Molecular To Macroscopic Understanding Of Chloroaluminate Anion Intercalation In Rechargeable Aluminum-Graphite Batteries, Jeffrey Xu

Dissertations and Theses

Today’s global energy challenges pose an urgent need to electrify transportation and better store intermittent renewable energy sources (e.g., solar and wind energy). For such large-scale battery applications, aluminum batteries are a promising “beyond lithium-ion” technology due to the high volumetric capacity, earth abundance, low-cost, and inherent safety of aluminum metal. However, there are very few compatible positive electrode materials that exhibit high energy density and cycling stability, in part due to the challenges of electrochemically intercalating highly charged Al³⁺ cations. Recently, graphite has been demonstrated as a promising positive electrode material in non-aqueous rechargeable aluminum batteries, which store …

Development Of An Injectable Methylcellulose Hydrogel System For Nucleus Pulposus Repair And Regeneration, Nada A. Haq-Siddiqi

Dissertations and Theses

Low back pain is the most common cause of disability in the world and is often caused by degeneration or injury of the intervertebral disc (IVD). The IVD is a complex, fibrocartilaginous tissue that allows for the wide range of spinal mobility. Disc degeneration is a progressive condition believed to begin in the central, gelatinous nucleus pulposus (NP) region of the tissue, for which there are few preventative therapies. Current therapeutic strategies include pain management and exercise, or surgical intervention such as spinal fusion, none of which address the underlying cause of degeneration. With an increasingly aging population, the socioeconomic …

Adsorption Kinetics And Phase Behavior Of Particles Adsorbed At An Interface, Shaghayegh Darjani

Dissertations and Theses

The ability to predict the adsorption dynamic, phase behavior, and surface pressure of a monolayer of adsorbed particles in two-dimensional systems are key aspects of many current research areas. Examples include phase transitions in amphiphilic monolayers, emulsion stability due to particle adsorption at interfaces, and melting at an interface.

In this thesis, a new approach for deriving the equation of state for a two-dimensional lattice gas is proposed, based on arguments similar to those used in the derivation of the Langmuir-Szyszkowski equation of state for localized adsorption. This work aims to predict the adsorption kinetics and phase behavior of a …

A Scoring Model To Evaluate Offshore Oil Projects: Case Of Eni And Mellitah Oil & Gas, Abdulhakim Giadedi

Dissertations and Theses

Offshore oil projects have many different and unique characteristics, such as larger project size, higher number of scopes, and higher complexity. In fact, offshore oil projects described as mega projects are ones that require significant assessment and acquisition methods in order to reduce risks and failures. Traditionally, cash flow analysis and return on investment are the most known factors to evaluate offshore oil projects. However, there are several other internal and external factors that affect the overall performance of offshore oil projects. A comprehensive approach and advanced tools are required to evaluate these factors that can have a significant impact …

Motion Of Janus And Patchy Particles Near Various Boundaries, Zohreh Jalilvand

Dissertations and Theses

Colloidal particles with anisotropic surface properties are an emergent class of novel materials that have been indicated to possess a remarkable potential to still be fully exploited. Among anisotropic colloids, Janus and patchy particles with different compositions and functionalities recently have drawn significant attention in the field of colloid science. They are known as promising candidates to address challenges in various fields such as emulsion stabilization, oil recovery, drug delivery, biosensors and environmental remediation. A majority of the envisioned applications require Janus and patchy particles to operate near boundaries, i.e., a wall or a fluid/liquid interface, which significantly affect the …

Investigation Of Asphaltene Adsorption At Liquid-Liquid And Liquid-Solid Interfaces, Fang Liu

Dissertations and Theses

Asphaltenes, as indigenous components in crude oils, are believed to play an important role in the petroleum production and processing industry. For example, asphaltene molecules can adsorb onto the water / oil interface like the amphiphiles and hinder water droplet coalescence, resulting in the stabilization of water-in-oil emulsions. Also, in the upstream production, depending on the temperature and pressure, asphaltenes can precipitate and deposit onto the reservoir rocks, the wellbores and the pipelines, leading to the change in reservoir rocks’ surface wettability and the blockage of the production facilities. Hence, it is crucial to understand the mechanism of asphaltenes adsorption …

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …

Electrochemical Properties Of Crystalline Polymorphs Of Mno2 In Aluminum And Zinc Metal Batteries, Subhadip Pal

Dissertations and Theses

The widespread use of non-renewable fossil fuels has led to societal problems like global warming and climate change. Electrochemical energy storage can enable the integration of renewable energy sources that are inherently intermittent (solar, wind, etc.) into the electric grid, though major advances in cost, cycle life, and safety are necessary to have a global impact on the energy landscape. Both aluminium (Al) and zinc (Zn) metals are earth abundant, low-cost, safe, and exhibit high coulombic capacities, which make them promising electrode materials for “beyond lithium-ion” battery chemistries. However, the electrochemical feasibility and charge storage mechanisms of alternative Al and …

Gas Hold-Up Measurements In 0.3 M Diameter Bubble Column: Effect Of Electrolytes, Heber Blanco De Brand

Dissertations and Theses

The present work reports the axial, radial and temporal gas hold-up profiles in a 0.3 m diameter batch bubble column using a pair of Wire Mesh Sensors and six pressure transducers.

Void Fraction Measurements In Large (0.3 M) Diameter Bubble Column Using Wire Mesh Sensor And Pressure Transducers- Effect Of Sparger, Afolabi Gabriel Ojo

Dissertations and Theses

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 …

Investigation Of The Synthesis And Optoelectronic Properties Of Ultrasmall Cdse Quantum Dots, Megan Webster

Dissertations and Theses

Traditional, or 1^st generation, solar cells have a theoretical upper limit of 33% power conversion efficiency based on the thermodynamic limitation of the single p-n junction cell design. This limitation is known as the Shockley-Queisser limit and methods to design solar cells to circumvent it have been creative, with a significant part of the field focused on quantum dot (QD) based systems. With theoretical efficiencies ranging between 44 and 67% for one sun concentration, QD solar cell designs are clearly superior to the limits of 1^st generation solar cells. However, maximum achieved efficiencies for QD-based designs are far …

Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan

Dissertations and Theses

Gamma-Secretase (γ-secretase) is a transmembrane protease of increasing interest, which has been shown to have significant connections to both cancer and Alzheimer’s disease. γ-secretase cleaves both Notch-1, a transmembrane signaling protein, and Amyloid precursor protein (APP), a transmembrane protein whose cleavage may result in the formation of β-amyloid plaques in the brain. Notch-1 and APP are widely studied proteins that have substantial impacts on the development and proliferation of cancer and Alzheimer’s disease, respectively. Notch-1 partakes in the signaling of apoptosis in damaged and mutated cells, thus its cleavage by γ-secretase within the plasma membrane has ramifications on cell growth …

Air Ingress And Heat-Driven Flow Relaminarization In A Very High Temperature Reactor (Vhtr), Apoorva Rudra

Dissertations and Theses

Very High Temperature Reactors (VHTRs) are one of six Generation IV reactors that have been proposed for DOE’s Next Generation Nuclear Plant. In addition to using gaseous coolants, VHTRs also display benefits of passive safety systems including intra-core natural circulation for heat removal in accident scenarios. However, a number of substantial engineering challenges are expected in VHTRs, and due to the high temperatures of the coolant involved, material behavior in various components needs to be better understood. Our work focuses mainly on two key phenomena that could lead to localized hot spots in the VHTR reactor core if not addressed …

Literature Survey Of Wet-Waste And Hydrothermal Carbonization System: A Comparative Evaluation, Ramat Olaide Yusuf

Dissertations and Theses

This thesis describes the process of Hydrothermal carbonization and a comparative assessment on recent work done on the process using different feedstocks such as Raw Apple (RA), Apple chip pomace (ACP), apple juice pomace (AJP), grape pomace (GP), macadamia nut-shell (MNS), Sewage Sludge (SS), Poultry Litter (PL) and Grape Marc (GM). The data obtained from the literature survey was compared with the data obtained by the CCL team on the SWPS gasifier (HTC of poultry litter) to obtain how carbon conversion efficiency, syngas composition, thermal efficiency, char production rate, gas production rate and energy utilization vary with carbonization process conditions, …

Microfluidic Study Of Gravity-Driven Drainage And Coalescence Of Aqueous Two Dimensional Foams, Justin D. Heftel

Dissertations and Theses

Foams, a two-phase dispersion, are staples of the cosmetic, personal care, petroleum, pharmaceutical, and other industries. Central to these applications is the stability of the dispersion against separation. Foams break down by two mechanisms: the first is bubble coalescence, which is driven by the gravity drainage of the continuous phase. The drainage acts to push the bubbles against each other, and leads to the formation of thin lamellae, which break and cause the coalescence. The second is the mass transfer of the dispersed phase through the continuous phase, which is caused by the difference in pressures between the bubbles and …

Void Fraction Measurements In A Large (0.3 M) Diameter Bubble Column Using Wire Mesh Sensors And Pressure Transducers: Effect Of Spargers, Afolabi G. Ojo

Dissertations and Theses

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 …

Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari

Dissertations and Theses

Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH₄, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m² m^-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …

Elucidation Of The Catalytic Partial Oxidation Of Methane Utilizing The One-Of-A-Kind Catalytic Shock Tube Technique, Robyn E. Smith

Dissertations and Theses

The mechanism for the catalytic partial oxidation of methane has been debated in scientific literature for over 20 years. This is a seemingly simple reaction producing CO, CO₂, H₂ and H₂O through either partial oxidation followed by complete oxidation or complete oxidation followed by reforming steps. What is happening when the reaction is allowed to occur in an environment absent of transport limitations, absent of temperature gradients and temperature changes, absent of boundary layers must be understood and, until now, has yet to be achieved in one experimental technique.

A novel method using a one …

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …