Transport Phenomena Commons^™

Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …

Water Recovery From Bioreactor Mixed Liquors Using Forward Osmosis With Polyelectrolyte Draw Solutions, Calen Raulerson

All Theses

The objective of this research was to test the feasibility of using forward osmosis (FO) with polyelectrolyte draw solutions to recover water from bioreactor mixed liquors. When combined with an Anaerobic Osmotic Membrane Bioreactor (AnOMBR), such a system could process fecal and food waste from astronauts aboard the International Space Station (ISS) and reclaim important nutrients and water. This project focused on measuring the obtainable water recovery rates from bioreactor effluent, and the identifying challenges associated with the operation.

AnOMBRs feature several advantages over aerobic bioreactors, and non-osmotic anaerobic membrane bioreactors (AnMBR). Anaerobic bioreactors avoid the significant energy costs of …

Towards Long Term Colloid Suspension In A Vertically Rotated System., Md Mahmudur Rahman

Electronic Theses and Dissertations

Within a colloidal suspension gravity may compromise the observation of governing physical interactions, especially those that are weak and/or take significant time to develop. Conducting the experiment in a long-term microgravity environment is a viable option to negate gravitational effects, though significant resources are required to do so. While it may not be possible to simulate long-term microgravity terrestrially, particles can resist quick sedimentation in a confined suspension system rotating vertically with appropriate rotation speed. The goal of the investigation is to demonstrate the existence of long-term particle suspension regime for a certain colloidal suspension while characterizing colloidal behavior due …

Preliminary Development Of The Dialysis-Membrane-Based Passive Biocide Delivery System For Spacecraft Water Recovery Units, Rogelio Elias Garcia Fernandez

Graduate Theses and Dissertations

The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in …

Cfd Simulations Of Macroscopic And Microscopic Multiphase Fluid Flow And Droplet Interaction, Aaron Harrington

LSU Master's Theses

Multiphase flow is a complex phenomenon which can be modeled on numerous different length scales, both macroscopically and microscopically. The use of a Euler-Euler model for Computation Fluid Dynamics (CFD) simulations of subcooled boiling phenomena is discussed in detail. The CFD conditions have been set up to mimic previous experimental conditions. A cylindrical vessel with subcooled liquid flow is heated along part of the axial wall of the vessel. A constant heat flux is applied to produce subcooled boiling. We discuss the development of the phase change within the vessel as well as the temperature profile, and validate the results …

Experimental Heat Transfer Investigations Of A Double Pipe U-Tube Heat Exchanger Equipped With Twisted Tape And Cut Twisted Tape Internals, Raj Kumar Nayak Maloth, Glen Cletus Dsouza, Swarna Mayee Patra

Mechanical and Materials Engineering Publications

For several decades, the use of heat exchangers for both heating and cooling applications has been established in industries ranging from process to space heating. Out of the various types of heat exchangers, U-tube heat exchangers are preferred owing to their abilities to handle larger flowrates and their simplicity in construction. U-tube exchangers are often equipped with innards of various forms which facilitate higher heat transfer rates and thermal efficiencies. Although higher heat transfer rates have been established with the addition of internals, there is a lack of coherence on the underlying complex physical phenomena such as heat transfer boundary …

Gum Arabic-Capped Silver Nanoparticles For Electrochemical Amplification Sensing Of Methylene Blue In River Water, Ziad Khalifa, Moustafa Zahran, Magdy Zahran, Magdi Abdelazzem

Chemical Engineering

Herein, a novel electrochemical amplification sensor is developed for detecting methylene blue (MB) us- ing gum Arabic-capped silver nanoparticles (AgNPs) for the first time. Gum Arabic-AgNPs were fabricated via a direct chemical reduction technique using silver nitrate as an AgNPs precursor and gum Arabic as a reducing and capping agent. They were characterized using ultraviolet-visible (UV–Vis) spectrophotom- etry, square wave voltammetry (SWV), and transmission electron microscopy (TEM). UV–Vis and SWV results show the characteristic absorption and electrochemical oxidation peaks of the AgNPs at 431 nm and 0.18 V, respectively. Additionally, TEM images of the AgNPs show that they are spherical …

Fully Coupled Internal Radiative Heat Transfer For The 3d Material Response Of Heat Shield, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The radiative transfer equation (RTE) is strongly coupled to the material response code KATS. A P-1 approximation model of RTE is used to account for radiation heat transfer within the material. First, the verification of the RTE model is performed by comparing the numerical and analytical solutions. Next, the coupling scheme is validated by comparing the temperature profiles of pure conduction and conduction coupled with radiative emission. The validation study is conducted on Marschall et al. cases (radiant heating, arc-jet heating, and space shuttle entry), 3D Block, 2D IsoQ sample, and Stardust Return Capsule. The validation results agree well for …

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion US dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a …

Analysis Of Fluid Flow In Redox Flow Batteries, Erfan Asadipour

McKelvey School of Engineering Graduate Student Theses & Dissertations

Redox flow batteries (RFB) hold great potential for large-scale stationary energy storage. However, their low energy density compared to other energy storage systems must improve for feasibility. Electrolyte flow distribution affects current density distribution and providing a uniform current density distribution is one way to improve RFB performance. Additionally, reducing the power consumption of the electrolytes’ pump as a source of energy loss in RFB systems increases their efficiency. Investigating both subjects requires analysis of the fluid dynamics in RFB cells.

In this thesis, a novel, computationally cost-effective hydraulic-electrical analogous model (HEAM) was developed to study fluid dynamics by implementing …

Image Analysis Of Charged Bimodal Colloidal Systems In Microgravity., Adam J. Cecil

Electronic Theses and Dissertations

Colloids are suspensions of two or more phases and have been topics of research for advanced, tunable materials for decades. Stabilization of colloids is typically attributed to thermodynamic mechanisms; however, recent studies have identified transport or entropic mechanisms that can potentially stabilize a thermodynamically unstable colloidal system. In this study, suspensions of silsesquioxane microparticles and zirconia nanoparticles were dispersed in a nitric acid solution and allowed to aggregate for 8-12 days in microgravity aboard the International Space Station. The suspensions were subsequently imaged periodically at 2.5x magnification. Due to the inadequacy of existing image analysis programs, the python package “Colloidspy” …

Graphical Design And Analysis Of Mass Exchange Networks Using Composition Driving Forces, Nessren Mohamed Farrag, Dina Ahmed Kamel, Ayat Ossama Ghallab, Mamdouh Ayad Gadalla, Mai Kamal Fouad

Chemical Engineering

Pinch analysis is a methodology for minimizing energy and mass consumption in different industries. It has been widely applied for more efficient processes. This study presents a new graphical-approach to analyze and design Mass Integration (MI) and exchange networks that follows Pinch principles to guarantee maximum mass recovery with minimum losses. This technique uses the composition driving forces in network representation as it rules the mass transfer between streams. The proposed approach can be applied on both existing mass networks as well as new ones. This graphical representation a visual descriptive design tool to describe and explain the details of …

Prediction Of Self-Diffusion Constants In Model And Real Systems Using Machine Learning, Joshua P. Allers

Chemical and Biological Engineering ETDs

Understanding diffusion of chemical compounds is important for the design and optimization of many chemical engineering and energy processes. Recent modifications to the Darken equation allow for accurate prediction of Maxwell-Stefan (MS) diffusion in mixtures. Still, there are few practical applications due to the requirement of individual self-diffusion constants. A reliable predictive model for self-diffusion constants would be highly valuable when used in conjunction with the modified Darken equation. Here, we show that Machine Learning (ML) can be used to develop generalized models for self-diffusion in Lennard Jones (LJ) systems and real systems of pure solutions. The use of Artificial …

Data-Driven Tools Guided By First-Principles For Scale Modeling, Sadegh Poozesh

Progress in Scale Modeling, an International Journal

For decades, traditional scale-modeling techniques have been relying on first-principles models (FPMs). FPMs have been used to find non-dimensional numbers (PIs) and identify normalized underlying forces and energies behind the phenomenon in focus. The two main challenges with FPM-based PIs extraction are finding the relevant PIs and proper correlations between PIs. The emergence and surge of data-driven modeling (DDM) provide a new opportunity to leverage experimental data in model development across scales/plants. In this paper, first, the two mentioned issues in PIs development will be elaborated to reveal the gap, and second, a new insight into scale modeling and similarity …

Improving The Accuracy Of Occupational Hygiene Models Used To Estimate Worker Exposure To Solvent Vapours, Spéro Abattan, Stéphane Hallé, Daniel Drolet, Ali Bahloul, Patrick Eddy Ryan, Wejden Chouchene, Carlos Castro Ruiz, Jérôme Lavoué, Maximilien Debia

Rapports de recherche scientifique

Chaque année, des travailleurs québécois subissent des effets sur leur santé après avoir été exposés à des substances chimiques, notamment à des solvants. La modélisation des expositions professionnelles occupe une place importante dans la prévention des risques. Cette recherche vise à étudier différents aspects de la modélisation pour estimer des expositions professionnelles à des vapeurs de solvants dans le but d’en améliorer la justesse de prédiction. Le travail de recherche a été effectué en deux volets. Grâce à la mise en œuvre de tests à petite échelle (volet I) et à échelle humaine (volet II), les travaux présentés dans cette …

Understanding Absorption, Supersaturation, And Drug Activity In Solution: Working Towards Developing A More Biorelevant Media, Freddy Arce

Theses and Dissertations--Pharmacy

With the looming dominance of poorly water-soluble chemical entities within the pharmaceutical pipeline, the pharmaceutical industry has leaned on the use of supersaturating drug delivery systems (SDDSs) to achieve efficacious concentrations within the gastrointestinal fluids. SDDSs aim to achieve concentrations in solutions greater than the solubility of the lowest energy crystalline form. However, the generation of supersaturated solutions of active pharmaceutical ingredients (APIs) creates a strong crystallization potential, which is undesirable.

In product development, supersaturating products often fail in Phase I and Phase II clinical trials due to poor oral bioavailability and a lack of in vivo efficacy. Pre-clinical testing …

Extraction Of Micro- And Nano-Plastic Particles From Water Using Hydrophobic Natural Deep Eutectic Solvents, Jameson R. Hunter

Theses and Dissertations--Biosystems and Agricultural Engineering

The production of plastic and the amount of waste plastic that enters the environment increases every year. Synthetic polymers will gradually break down into particles on the micro- and nano-scale. The micro- and nano-plastics pose a significant ecological harm by transporting toxic chemicals and causing inflammation and cellular damage when ingested. Two common plastics are polyethylene terephthalate (PET) and Polystyrene (PS), and a newer bioplastic polylactic acid (PLA) that has become a popular alternative. Deep eutectic solvents are a recently discovered solvent composed of a hydrogen bond donor and hydrogen bond acceptor and have been proposed as a cheaper alternative …

Assessing Solvent Viscosity Impact On The Physical Characteristics Of Polymeric Organogels, Cameron Hong

Honors Theses

Traditionally, studies of polymeric organogels focus on the impact of polymer factors (e.g., molecular weight and polymer concentration) on the gels’ mechanical and transport properties. Alternatively, this study seeks to assess the impact of altering solvent viscosity, while holding polymer factors constant. The gels in this study were composed of different viscosity mineral oils, styrene-ethylene-butylene-styrene (SEBS) triblock copolymer as a gelator, and oleic acid (OA) as a model drug. Samples were formulated to have 6.5, 11.2, and 15.7 wt% SEBS copolymer for each mineral oil, varying in viscosity from ≈30 mPa*s to ≈500 mPa*s. Uniaxial mechanical testing was performed to …

Assessing The Impact Of Block-Selective Homopolymers On The Diffusion Of Payload Through Polymeric Organogels, Ian Coates

Honors Theses

Styrenic polymer gels have received recent attention for their application in transdermal patches due to their unique properties. Previous research in the pharmaceutical industry has identified that polymeric gels, specifically styrenic gels, have the potential to encompass multiple functions of the transdermal delivery patch including controlling mechanical and delivery properties. To tailor styrenic gels either the gel nanostructure or the drug complex can be controlled. Specifically, this thesis investigated the effect of gel nanostructure in an attempt to control the gel diffusivity and mechanical properties. To control gel nanostructure a phase selective styrene homopolymer was used at varying concentrations. It …

Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin

Master’s Theses

Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …

Testing The Effectiveness Of Various Fabrics For Use In Protective Face Coverings, Isaac Daley

Williams Honors College, Honors Research Projects

Facemask requirements have been heavily implemented as a result of the COVID-19 pandemic. The purpose of this study was to test various fabrics that could be used in face coverings and determine which materials are best for reducing virus transmission rates. Of the seven fabrics tested, five were conventional home-use fabrics and the other two were surfaces modified with hydrophobic organosilanes. Wettability and droplet adherence tests were performed on each material. The materials that performed the best were decyltrichlorosilane (DTS) modified cotton, perfluorotrichlorosilane (FTS) modified cotton, and polyester. Contact angles for water droplets on these fabrics were 106°, 93°, and …

Simulation Of Water Loading In Filter Medium, Anthony Mole

Williams Honors College, Honors Research Projects

This research will model fluid flow through a filter plugged with water droplets using FlexPDE software. After simulations are run at various initial conditions, curves will be developed to correlate the permeability of the filter to variables like water droplet distribution and size.

Relating Modified Ergun's Equation To Hindered Settling Correlations, Ryan Zahniser

Williams Honors College, Honors Research Projects

Correlations were developed between the Modified Ergun’s and Hindered settling correlations under the condition of dense packing of particles in the bed. As the porosity of the slurry increases, so does the interference between particles in the solution which mimics the behavior of a packed or densely concentrated fluidized bed. The similarity between the two sets of conditions was modeled using mathematical equations to calculate settling velocities and pressure drops by means of the Hindered Settling correlations and Modified Ergun’s equation at porosities ranging from 0.4242 to 0.89. The results showed that a porosity of 0.52 and 0.009 ft particle …

The Effects And Motion Of An Air-Filled Cylinder Being Submerged In Water In The Axial Direction, Ethan Davis

Williams Honors College, Honors Research Projects

Submarines operate on the basis of a difference in relative densities between of vessel and the surrounding fluid. This principle is based on the force balance that exists between the total buoyancy force and the force due to gravity. Previous work focuses on the neutral buoyancy depths and velocities of object that once submerged, their buoyancy force is a constant along with the force due to gravity. This work aims to better understand how the compression of air at various depths below the surface of the water contribute to the neutral buoyancy depth, velocity of the object as it rises, …

Effects Of Microporous Structure On The Enzymatic Conversion Of Biomass Using A Multiscale Model, Saketh Merugu

Dissertations, Master's Theses and Master's Reports

The generation of biofuels from lignocellulosic biomass involves innovative process technology that is being investigated worldwide. Enzymatic hydrolysis is a major step in the contemporary process of the generation of biofuels. Guided by pore size distribution measured using NMR cryoporometry, we developed pore-enzyme diffusion and adsorption models at the particle level coupled with a kinetic model for cellulose, cellobiose, and glucose production at flask level. By simulating these models in MATLAB, COMSOL, and Polymath software packages, we investigate the effects of various biomass particle-related parameters (particle dimensions, porosity, enzyme accessibility) on the characteristic time of enzyme diffusion and adsorption and …

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 …

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 …

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 …

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 …