Chemical Engineering Commons^™

Probing Counterion Condensation Phenomena In Nanostructured Thin Film Block Copolymer And Random Copolymer Electrolytes, Qi Lei

LSU Doctoral Dissertations

This dissertation describes advanced metrology and molecular dynamics simulations for quantifying counterion condensation in block copolymer electrolyte thin films. The fraction of condensed counterions (f_c) were quantified in nanostructured block copolymer electrolyte (BCE) and random copolymer electrolyte (RCE) thin films with new and established experimental techniques. The transition between the osmotic-controlled regime and condensation-controlled regime in BCEs and RCEs was identified using solution uptake measurements via a quartz crystal microbalance (QCM) and environmental grazing incidence small-angle x-ray scattering (GI-SAXS). The activity coefficients of ions in thin film were quantified experimentally and these values matched predictions from Manning’s Theory …

Engineering Dopant Position In Structure-Controlled Ceo2-Zro2 Catalysts, Behnam Safavinia

LSU Master's Theses

CeO₂-ZrO₂ (CZO) nanoparticles (NPs) have application in many catalytic reactions, such as methane reformation, due to their oxygen cycling ability. Ni doping has been shown to improve the catalytic activity and acts as an active site for the decomposition of methane. In this work, Ni:CZO NPs were synthesized via a two-step co-precipitation/molten salt synthesis to compare Ni distribution, oxygen vacancy concentration, and catalytic activity relative to a reference state-of-the-art catalyst. To better understand the effects of Ni position and dispersion, and oxygen vacancy formation in these materials, the Ni concentration, reaction time, and deposition methods were varied. …

Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal

LSU Doctoral Dissertations

Water scarcity and energy availability present important challenges that need to be addressed in the coming centuries. In the front of water technologies, desalting brackish water is of extreme importance for thermal electric power plants, chemical manufacturing plants, and other industrial operations that treat and reuse their water utilities. Membrane capacitive deionization (MCDI) is an energy efficient desalination technique that has drawn attention from commercial entities. Most material research studies on MCDI focus on enhancing electrode performance while little emphasis is given to rationale design of ion-exchange membranes (IEMs). In this work, the ionic conductivity, permselectivity, and thickness for three …

Theoretical Investigation Of Fundamental Cathode Processes In Metal-02 Batteries, Saurin Hiren Rawal

LSU Doctoral Dissertations

In this thesis we theoretically explore the different fundamental phenomena associated with metal-air batteries (where the metal can be Li, Na or K) using first principles density functional theory. We start by investigating the adsorption of the starting reactants/primary intermediates i.e. metal superoxides and superoxide anion on Au(111) and Au(211). We elucidate the influence of electric fields and the importance of including explicit solvents on the adsorption energy of these intermediates. We show that these effects are considerable and should be included for future reaction modeling of these batteries. Following this we investigate the reaction of M⁺ and O …

Internals In Gas-Liquid Systems, Sai Sankar Ganesan

LSU Doctoral Dissertations

The objective of this study is to model gas-liquid contact and separation problems (using Euler-Euler based Computational Fluid Dynamic (CFD) models) at different scales. We have explored process intensive solutions, design optimizations by introducing internals in these gas-liquid operations.

A 500L pilot plant scale and a 7000L industrial scale novel down-flow bubble column problems were modeled. Methodologies used to overcome challenges on large-bubble micro-bubble dynamics are discussed and the resulting fluid dynamic solutions were studied. These solutions were further modified and tailored toward intensification, by exploring horizontal plate internals. We then modeled mass transfer and reaction kinetics on this system …

Tunable Luminescence Of Rare Earth Doped Nanophosphors Via Adaptive Optical Properties Of Transition Metals, Pragathi Darapaneni

LSU Doctoral Dissertations

Over the past decades, the development of light-emitting diodes (LEDs) to produce a wide range of wavelengths has revolutionized the solid-state lighting industry due to their higher energy efficiency and operational lifetimes. These LEDs employ rare earth (RE) doped phosphors due to their stable emission wavelengths which can be amplified when sensitized by other RE dopants (Yb, Ce) or shell layer passivation. However, there has been a push to replace the RE elements in LEDs due to increased socioeconomic issues. One proposed alternative, transition metal (TM) dopants, is typically avoided due to their susceptibility to the local crystal environment resulting …

Transition Metal-Doped Rare-Earth Oxysulfide Catalysts For High Temperature Dry Reforming Of Methane, Changyi Jiang

LSU Doctoral Dissertations

Carbon dioxide reforming of methane is a catalytic reaction utilizing two kinds of greenhouse gases and converting them into a useful industrial gas stream, “syngas”. However, sulfur poisoning and coke formation are two major challenges for this reaction. In this study, we have synthesized and examined several Ce-La and Ce-Zr oxides, with different transition metal additives. A rapid screening technique was developed to measure reforming and coking rates at low partial pressures. It is a good indicator of catalyst behavior at higher conversions and partial pressures. Following the rapid screening, select catalysts were examined at longer times on stream. Those …

Investigation Of Tracer-Surfactant-Foam Processes In Shallow Subsurface Environmental Remediation: History-Matching And Performance Prediction, Hazem Fleifel

LSU Master's Theses

In-situ subsurface remediation has been widely used as an efficient means of cleaning up non-aqueous phase liquid (NAPL) from contaminated soils and aquifer. The use of tracer, surfactant, and foam are often considered to keep track of the propagation of injected fluids in the medium, dissolve and mobilize contaminants trapped by capillary forces, and overcome the level of heterogeneity and improve displacement and sweep efficiencies.

This study shows an actual remediation process to reduce NAPL within a military base in South Korea, by injecting tracer and surfactant solutions together for a duration of 10 days. The site consists of 5 …

Noble-Transition Alloy Absorbers For Near-Infrared Hot-Carrier Optoelectronics, Sara Karoline Figueiredo Stofela

LSU Doctoral Dissertations

Optoelectronics is the field of technology concerned with the study and application of electronic devices that source, detect and control light. Here we focus on the optical communications field which relies on optical fiber systems to carry signals to their destinations operating in the near-infrared range. To improve the performance of current optical fiber systems, one of the paths is to develop better near-infrared photodetectors.

The current group of materials used for near-infrared photodetection relies in the III-V semiconductor family. Although their spectral photosensitivity correlates well with the near-infrared, response time performance and electronic circuit integration remain limited for this …

Experimental And Computational Tools For Single Cell Analysis In Cancer Diagnostics, Manibarathi Vaithiyanathan

LSU Doctoral Dissertations

Substantial evidence shows that cellular heterogeneity commonly exists within an isogenic or clonal population. Whether in isolation or caused through a combination of the above events, cellular heterogeneity can dramatically influence cellular decision making and cell fate, however, this can be masked by the average response from a population. One approach to solve this issue is to analyze a population at the individual cell level. The goal of this work is to develop high-throughput experimental and computational platforms to screen and quantify single cancer cells for specific intracellular enzyme activities. An interdisciplinary approach was taken to 1) better understand the …

Experimental Evaluation Of How Mineralogy And Microstructure Impact Micro-Geomechanics Of Shale Rocks, Hui Du

LSU Doctoral Dissertations

Shales play an essential role in petroleum exploration and production because they can occur either as unconventional reservoir rocks for hydrocarbon extraction via hydraulic fracturing or as caprocks for conventional reservoirs and subsurface gas/ waste storage. For both extraction and storage applications, the success rate is directly depending on the rigorous candidate selection. Conventional rock characterization techniques normally measure rock properties by seismic/logging at the reservoir scale, and on drilled/outcrop cores at the core scale. However, shales are highly heterogeneous in composition, containing a large number of reactive minerals in micro/nanoscale with significantly different properties. The structural features and properties …

The Desorption Kinetics Of Methane From Nonaqueous Fluids For Enhanced Well Control, James Lee Nielsen Jr.

LSU Master's Theses

The mass transfer of a dissolved gas evolving to return to the gaseous phase from a liquid is governed by many parameters. This process affects the development of an oil and gas well due to the possibility of gas contamination occurring from either an influx entering the wellbore, or drilling through gas-bearing formations. Once this dissolved hydrocarbon gas circulates up the wellbore, it will begin to evolve from solution and poses a potential risk to drilling equipment, the environment, and personnel at a drilling rig. Being able to predict the behavior of gas desorption based on a known set of …

First-Principle Study On The Interaction Of Ligands With Gold And Effects On Catalytic Activities, Xun Cheng

LSU Doctoral Dissertations

The extensive use of fossil fuels has increased the atmospheric concentration of CO₂, resulting in global climate change. One way to mitigate the CO₂ challenge is to convert it into useful chemicals electrocatalytically using renewable energies. Recent studies suggest that ligand-modified gold electrodes can enhance the Faradaic efficiency (FE) and selectivity of the electrochemical CO₂ reduction reaction (CO₂RR). This theoretical research, primarily based on density functional theory (DFT), has been carried out to understand the interactions of ligands with Au and possible effects on electrocatalytic activities. We systematically modeled and studied the adsorption of …

A Study Of Particle-Laden Flows From Meso And Micro-Scale Perspectives, Daniel Guedes De Oliveira

LSU Doctoral Dissertations

Particle-laden flows are investigated numerically from a meso-scale perspective using Computational Fluid Dynamics coupled with Discrete Element Method (CFD-DEM) and from a micro-scale perspective using Particle Resolved Direct Numerical Simulation (PR-DNS). For the former, the dynamics of a pseudo-2D pulsed fluidized bed (PFB) consisting of 400,000 to 800,000 particles was investigated (Chapters 2 and 3). The focus is on the capabilities of CFD-DEM to (1) reproduce pattern formation in these systems and (2) further the understanding of the dynamics of PFB's as a function of pulsation parameters. In Chapter 4, a two-spheres system is investigated with a recently implemented PR-DNS …

Synthesis Of Lamno3 & Ceo2-Mnox Nanocrystals For Selective Catalytic Reduction, Joseph Lane

Honors Capstones

No abstract provided.

Breaking Coastal Hypoxia: Destratification Of Gulf Of Mexico Deadzone To Encourage Oxygen Transport Downwards To Maintain Marine Fauna, Veda Thipparthi

LSU Master's Theses

As a consequence of seasonal eutrophication and human input, a vast hypoxic area termed The Dead Zone develops every year in the Gulf of Mexico (GOM) during summer along the Louisiana coastline characterized by vertical seawater density-stratification with oxygen concentrations less than 2 mg.l^-1 at the seafloor. It poses a threat to bottom-dwelling faunae and their environment which has negative ecological and economic consequences. This project aims to mitigate hypoxia by employing mechanical impellers placed at strategic water depths and locations in the Gulf. Enhanced transport of oxygen results by mixing oxygen-enriched seawater at the surface, downward into the …

The Effects Of Temperature On The Yields Of Aliphatic And Aromatic Products From The Supercritical Pyrolysis Of 1-Octene, Elizabeth Anne Hurst

LSU Doctoral Dissertations

Prior to their combustion, fuels for future high-speed aircraft are expected to experience supercritical conditions, leading to the production of polycyclic aromatic hydrocarbons (PAH), precursors to solid carbonaceous deposits, via pyrolytic reactions. These solid deposits can clog fuel-transfer lines, causing unsafe aircraft operation. To prevent the formation of fuel-line deposits, it is critical to understand the reaction pathways that lead to PAH formation in the supercritical fuel pyrolysis environment.

To better understand the role of large 1-alkenes in PAH formation, supercritical pyrolysis experiments with model fuel 1-octene, a representative 1-alkene product from supercritical n-alkane pyrolysis, have been performed. The …

The Ability Of Β-Hairpin Peptides To Function As Degradation-Resistant, Cell-Penetrating Peptides And Their Potential As Proteolysis Targeted Chimeras, Jeffery C. Anderson

Honors Capstones

No abstract provided.

Effect Of Surfactant, Oil:Water Ratio And Temperature On The Rheology Of Emulsion-Suspension Complex Fluids: Implications For Oil-Based Drilling Fluids, Gilles Landry Numkam

LSU Doctoral Dissertations

Drilling fluids are non-Newtonian mixtures that play a critical role in the timely and successful completion of oil and gas wells. In the particular case of offshore operations, proper design of drilling fluids is of paramount importance in the constant quest to lower break-even prices. Most downhole problems are directly or in-directly related to the rheological and physical properties of drilling fluids, thereby calling for a better understanding of the underlying changes of these properties with respect to drilling fluid composition and external conditions.

The current stance in the design of drilling fluids involves the selection of components and their …

Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding

LSU Doctoral Dissertations

Multiphase modeling is prevalent and useful in solving problems involving multiphase interactions such as fluid and solid. Applications conclude but not limited to fluidized bed, hydraulic conveying, and many others. Modeling techniques with multiple scales can provide various states of details with diverse computational resources used. In this dissertation, two CFD multiphase models are used to disclose interaction details in the particulate system. Two-Fluid Model is used to solve pulsed fluidized bed problem and immersed boundary method based direct numerical method is used to solve particle’s behavior in shear flow. Getting a better understanding of these problems to help to …

Application Of Pressure And Rate Transient Analyses To Stress-Sensitive Multi-Fractured Composite Systems And Compartmentalized Reservoirs, Oscar Mauricio Molina

LSU Doctoral Dissertations

Pressure transient analysis (PTA) is one of the most robust and commonly interpretation tools available for reservoir characterization. Common applications of PTA include estimation of near-wellbore and reservoir properties, detection of reservoir limits and identification of depletion mechanisms. In addition, PTA allows the identification of sealing and leaky faults and the characterization of its properties, such as permeability and transmissibility hence direction of leakage within the fault.

The purpose of this dissertation is to introduce the analytical solution for pressure-transient behavior for three novel reservoir models. First, we develop the analytical model of a multi-fracture horizontal well (MFHW) with pressure-dependent …

Field Drilling Data Cleaning And Preparation For Data Analytics Applications, Daniel Cardoso Braga

LSU Master's Theses

Throughout the history of oil well drilling, service providers have been continuously striving to improve performance and reduce total drilling costs to operating companies. Despite constant improvement in tools, products, and processes, data science has not played a large part in oil well drilling. With the implementation of data science in the energy sector, companies have come to see significant value in efficiently processing the massive amounts of data produced by the multitude of internet of thing (IOT) sensors at the rig. The scope of this project is to combine academia and industry experience to analyze data from 13 different …

Maximizing And Modeling Malonyl-Coa Production In Escherichia Coli, Tatiana Thompson Silveira Mello

LSU Master's Theses

In E. coli, fatty acid synthesis is catalyzed by the enzyme acetyl-CoA carboxylase (ACC), which converts acetyl-CoA into malonyl-CoA. Malonyl-CoA is a major building block for numerous of bioproducts. Multiple parameters regulate the homeostatic cellular concentration of malonyl-CoA, keeping it at a very low level. Understanding how these parameters affect the bacterial production of malonyl-CoA is fundamental to maximizing it and its bioproducts. To this end, competing pathways consuming malonyl-CoA can be eliminated, and optimal nutritional and environmental conditions can be provided to the fermentation broth. Most previous studies utilized genetic modifications, expensive consumables, and high-cost quantification methods, making …

A Model-Based Framework For The Smart Manufacturing Of Polymers, Santiago D. Salas Ortiz

LSU Doctoral Dissertations

It is hard to point a daily activity in which polymeric materials or plastics are not involved. The synthesis of polymers occurs by reacting small molecules together to form, under certain conditions, long molecules. In polymer synthesis, it is mandatory to assure uniformity between batches, high-quality of end-products, efficiency, minimum environmental impact, and safety. It remains as a major challenge the establishment of operational conditions capable of achieving all objectives together. In this dissertation, different model-centric strategies are combined, assessed, and tested for two polymerization systems.

The first system is the synthesis of polyacrylamide in aqueous solution using potassium persulfate …

Nanoparticle Burst Timing Optimization, Simon Grigoryan

Honors Capstones

No abstract provided.

Microfluidic Generation Of Orthogonal Chemical Gradients To Study Cellular Decision Making During 3d Migration, Joshua M. Campbell

Honors Capstones

No abstract provided.

Hierarchal Control Of Magnetic Metal Oxide Nanoparticles, Hunter Simonson

Honors Capstones

No abstract provided.

Design And Optimization Of A Microfluidic Device To Study The Effects Of Fluid Shear Stress On Extravasation, Joseph B. Balhoff

Honors Capstones

No abstract provided.

Natural Gas Conversion Into Value Added Chemicals Using Solid Acid Catalysts, Swarom Ravindra Kanitkar

LSU Doctoral Dissertations

Direct, non-oxidative conversion of natural gas to value-added chemicals has been identified as one of the grand challenges of the 21^st century. Circumventing indirect and costly reforming steps is highly sought after and solid acids can play an important role in that.

The direct conversion of methane to higher hydrocarbons and hydrogen can be catalyzed using “superacids” at < 450 °C. Reported superacid catalysts in solid, liquid, and gas phase included sulfated zirconia (SZ), HF-SbF₅, FSO₃H-SbF₅, and HBr-AlBr₃. Liquid and gas phase superacids presented difficulties in separation while the solid ones provided low yields. Here, we report a new class of Br-based solid superacids, AlBr_x/H-ZSM-5 (“ABZ-5”, …

Theoretical Investigation Of The Ring Opening Of Cyclohexane On Ir(111) And Pt(111), Kushal Ghale

LSU Master's Theses

Diesel engines have higher fuel efficiency and can burn cleaner than gasoline engines. To enhance quality of diesel fuels as measured by the cetane number (CN), the removal of aromatic compounds is necessary. A potentially highly efficient approach would be to convert aromatics to saturated cycloparaffin, followed by selective ring opening to linear or branched alkanes, to increase the CN. Here the focus of the project is to study the mechanism of metal-catalyzed ring opening (RO) of cyclohexane (denoted CHA, or c-C₆H₁₂) through theoretical and computational modeling. CHA, a simplest cycloparaffin, is used as probe molecule …