Chemical Engineering Commons^™

Numerical Studies Of Flow In Porous Media Using An Unstructured Approach, Nathan Matthew Lane

LSU Doctoral Dissertations

Flow and transport in porous media is relevant to many areas of engineering and science including groundwater hydrology and the recovery of oil and gas. Porous materials are characterized by the unique shape and connectivity of the internal void structures which give rise to a large range in macroscopic transport properties. Historically an inability to accurately describe the internal pore-structure has prevented detailed study of the role of pore structure on transport. In recent decades however, the combination of high resolution imaging technologies with computational modeling has seen the development of fundamental pore-scale techniques for studying flow in porous media. …

Catalytic Process For The Conversion Of Synthesis Gas To Ethanol For Use As An Alternative Fuel, Nitin Kumar

LSU Doctoral Dissertations

Higher alcohols are increasing as a proportion of the transportation fuel market, and can be used as neat fuels, or as blends with conventional fuels. For a number of reasons, these C2+-alcohols will be of interest in the foreseeable future. Large-scale production of higher alcohols will likely be carried out via syngas, which can be produced from a number of feedstocks, including coal, natural gas and biomass. Rhodium-based catalysts have been found to be the most active/selective for higher alcohols. However, the literature shows that the yields of C2+-alcohols that can be achieved with current catalysts, even the most active/selective, …

Characterization Of Foam Flow In Pipes Using Two Flow Regime Concept, Rahul Narayanrao Gajbhiye

LSU Doctoral Dissertations

The objective of this study is to investigate the characteristics of foam flow behavior in pipes in a wide range of experimental conditions, including two pipe materials (stainless steel and nylon pipes with about 0.36 - 0.38 inch in inner diameter and 12 ft in length), three surfactant formulations (Cedepal FA-406, Stepanform-1050, and Aquet-944), and three surfactant concentrations (0.1, 0.5, and 5 wt%). The concept of “two foam-flow regimes”, consisting of high-quality regime and low-quality regime, is at the heart of interpreting the experimental data. The experimental results in horizontal pipes showed the presence of two distinct high-quality and low-quality …

Surface Functionalization Of Crystalline Silicon Substrates, Sri Sai Vegunta

LSU Doctoral Dissertations

In this work, various chemical and electrochemical methods were demonstrated to attach application-specific organic monolayers to crystalline silicon substrates. In one study, alkyl monolayers were anodically electrografted or thermally grafted onto planar (100) silicon substrates using Grignard precursors. The results show electrografted methyl monolayers provide a stable Si-C termination, resisting oxidation on (100) surfaces for approximately 55 days in air. The alkyl termination could provide a potential alternative to defective native oxides and kinetically unstable hydride surfaces. A mechanism involving two electron transfers per grafting event was established for both the thermal and electrochemical routes. In another study, unsaturated organic …

Photochemical Reaction Products Of Polycyclic Aromatic Hydrocarbons Adsorbed At An Air-Water Interface, Franz Stefan Ehrenhauser

LSU Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants resulting from incomplete combustion and hence normally unavoidable. The kinetic aspects of the environmental degradation process have received considerable attention; however, not much is known about the degradation products themselves. Aqueous solutions of naphthalene, acenaphthene, 9H-fluorene, phenanthrene and pyrene were subjected to UVB light in a bulk-phase and a thin-film reactor to assess the identity of the formed photodegradation products. To aide in the challenging analysis of these mixtures, a novel analytical technique based on high performance liquid chromatography (HPLC) coupled to UV diode-array detection and dopant-assisted atmospheric pressure photoionization mass …

Preparation And Characterizations Of Lithium Titanate (Li4ti5o12)., Nor Aini Alias

Student Works (2010-2019)

Li4Ti5O12 is a potential anode material for lithium-ion batteries. This serves as the motivation for the present study. Li4Ti5O12 compound has been obtained through the sol-gel technique. From thermo gravimetric analysis, Li4Ti5O12 is thermally stable at temperatures above 700 oC. Organic compounds are observed to decompose at 600 oC and below. From XRD diffractograms peaks due to Li2TiO3 and anatase TiO2 phases observed, Li4Ti5O12 has a cubic structure. The lattice parameters for all Li4Ti5O12 are sintered at different temperatures and times are approximately 8.3 Å. The discharge capacity of a cell employing Li4Ti5O12 as electrode is ~60 mAh g-1 for …

Extraction Of Chromium From Wastewater By Emulsion Ionic Liquid Membrane., Rahul Kumar Goyal

Student Works (2010-2019)

Emulsion liquid membrane (ELM) has been proven to be a competent extraction technology to extract heavy metals or organic compounds from industrial wastewaters. In this process, a prepared emulsion is dispersed into a feed phase which contains the solute to be removed. Single stage operation and less power consumption make this technology more favorable over pressure-driven membrane process and solvent extraction. Despite its comparative advantages, ELM process suffers from emulsion instability and swelling under high shear and stress during extraction, causing breakage in the membrane. The instability and swelling of the emulsion allow extracted solute and internal reagent to mix …

Mechanical Characterization Of Polymer Electrolyte Membrane With Optical Methods, Xinyu Huang, Luis Alva, Jay Neutzler

Faculty Publications

Mechanical properties of polymer electrolyte membrane have important implications in the endurance of many electrochemical energy conversion devices [1]. Mechanical experiments are effective method to reveal discrete damage developed in the membrane by quantifying the change of mechanical strength and toughness. Regular strain measurement methods are overly intrusive to the thin and relatively fragile polymer electrolyte membrane; hence optical-based minimal invasive stress/strain measurement methods are studied.

Synthesis And Energy Applications Of Oriented Metal Oxide Nanoporous Films, Qingliu Wu

University of Kentucky Doctoral Dissertations

This dissertation mainly addresses the synthesis of well-ordered mesoporous titania thin films by dip coating with PEO-PPO-PEO triblock copolymer surfactant template P123. Because P123 is composed of poly(ethylene oxide) [PEO] and poly(propylene oxide) [PPO] blocks, concentrations of ingredients are adjusted to tune the films’ wall thickness, pore size and mesophase. Structural changes are consistent with partitioning of species among PEO blocks, PPO blocks, and the PEO/PPO interface. Titanates localize near PEO and increase wall thickness (by 5 nm to 7 nm). Depending on aging temperature, PPG either swells the PPO cores (when it is hydrophobic) or introduces large (>200 …

Development Of A Waterjet System For Direct Delivery Of Granular Iron And Activated Carbon To Remediate Contaminated Aqueous Sediments, Gavin H.R. Risley, Andrew Curtis Elmore, Joel Gerard Burken, Grzegorz (Greg) Galecki

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

While the Techniques and Technologies Associated with Contaminated Sediment Remediation Are Relatively Mature, There Are Several Issues Associated with These Practices that Make Them Unattractive. the Inability of Currently Used Mechanical Mixing Implements to Place Amendments in Aqueous Environments and their Intrusive Behavior toward Benthic Communities Are Just Two Examples of a Necessity for an Improved Delivery Method. Waterjets May Be a Viable Option for Placement of Particulate Remediation Amendments, Such as Activated Carbon and Granular Iron, at Depth. a Custom Waterjet Nozzle and Injection System Has Been Fabricated by the Authors to Examine This Delivery Concept. the Developed Injection …

Thermomechanics Of Curves In Space, Pavan Krishna Kanchi

Masters Theses

"Several biological molecules are known to form helices and coiled structures, such as DNA, collagen, bacterial flagella, and proteins. The backbones of such molecules may be modeled as a curve in three dimensions. A variational problem for the functional of the total free energy required to perturb moving curves in space is considered. The total energy of a curve in three dimensions is minimized y with a general intensive energy, which is a function of position, and the invariants, curvature and torsion. Three types of moduli are identified: stretching, bending and torsional moduli. As a result, three independent force balances …

Numerical Simulation Of Relative Permeability Modifier Effect On Oil And Water Production, Murad Mohammedahmed Abdulfarraj

Masters Theses

"Excess water production is one of the most prevalent operational problems that oil companies are facing. Polymers and polymer gels have been used widely to control excess water production for mature oilfields. It is well known that polymers/gels can reduce the permeability to water (Krw) much more than that to oil (Kro). This phenomenon is called disproportionate permeability reduction (DPR) and the polymers or gels that exhibit this behavior are called relative permeability modifier (RPM). When RPMs are placed in reservoir, reduced permeability to water can lead to decreased water production, and sometimes increased hydrocarbon production, therefore prolonging the useful …

Hybrid Inorganic/Organic Nanostructured Tandem Solar Cells: Simulation And Fabrication Methods, Patrick Michael Boland Jr.

Electrical & Computer Engineering Theses & Dissertations

Organic solar cell technologies continue to be an extremely active area of scientific research. With their promise of providing low-cost, easily-processable, multi-application photovoltaics, these devices could very possibly be the most viable and practical form of renewable energy among many being explored. However, significant technological obstacles remain that must be overcome if this technology is to successfully realize the goal of providing abundant energy while simultaneously reducing dependence on fossil fuel-based sources. Compared with inorganic solar photovoltaics, power conversion efficiencies in organics are still too low to compete economically.

Much research has been accomplished over the past three decades in …

The Feasibility Of Using Bifidobacteria Bifidum (Atcc 700541) For The Production Of Prebiotic Oligosaccharides, Candice Marie Luehrs

Masters Theses

"Galactooligosaccharides (GOS) are prebiotics that are being used to influence intestinal microbiota towards health promoting, beneficial bacteria like bifidobacteria. Natural sources of GOS are not found in suitable levels to achieve the desired health effects so economically viable commercial production methods are important. Enzymatic conversion of lactose to GOS through transgalactosylation is a preferred method since the starting material is inexpensive and readily available. Enzymes used in batch production are purified from fungal or bacterial sources or remain in whole cells cultured for GOS production. Purified or unbound enzymes are single use whereas enzymes retained within whole cells can potentially …

Biodegradable Polymer/Clay Nanocomposites Based On Poly(Butylene Adipate-Co-Terephthalate) And Polylactide, Mahin Shahlari

Doctoral Dissertations

"In offering a scientifically succinct methodology which leads to property-enhanced biodegradable polymer products for broader application, as well as in promoting the use of bio-sourced renewable polymers such as Polylactide (PLA) in biodegradable polymers with desirable properties from petroleum based polymers such as PBAT, this study and its results both directly and indirectly contribute to the technological solutions that address growing environmental and energy problems caused by the increased use of and reliance upon nondegradable, nonrenewable, petroleum-based plastics. This work studied blends of PBAT and PLA compounded with organoclay through direct melt mixing in a twin-screw extruder and a batch …

Enhanced Heavy Oil Recovery By Alkali-Surfactant In The Pennsylvania Warner Sandstone, Rabia Mohamed Hunky

Doctoral Dissertations

"In this research, a study of the non-thermal method of alkaline-surfactant (AS) flooding to enhance heavy oil recovery from the Pennsylvanian Warner sandstone reservoir in Western Missouri was conducted. This work includ [sic] testing approximately 30 commercial surfactants and using a heavy oil sample with an API of 17. It was found that a number of surfactants could create stable emulsions. The viscosity of heavy oil could be reduced from 18,518 cp to 2.5 cp at 25⁰C through emulsification of certain surfactants. One of the major findings was that the emulsion created by the commercial surfactant, Igepalʼ CO-530 was stable …

Effect Of Hydrophobicity And Surface Roughness On Two-Phase Flow In Rectangular Microchannels, Gautham C. Unni

Doctoral Dissertations

"Two-phase flows in microchannels have received significant attention recently, and have become the cornerstone of numerous microfluidic devices. Microscale devices used for bioengineering applications, oil recovery, and chemical and catalytic microreactor applications involve the transport of bubbles in confined fluidic networks in channels of micrometer length scale. These types of two-phase flows result in pressure variations, leading to an overall increase in pressure drop. Among various flow parameters, pressure drop is extensively used in design of microfluidic devices. There are several parameters that affect the pressure drop across two-phase flow in microchannels. In the present study, the goal is to …

Strength Adjustable Preformed Particle Gels For Conformance Control, Jia Zhou

Doctoral Dissertations

"Reservoir heterogeneity and early water breakthrough (also known as fingering) represent two of the greatest challenges to recover crude oil efficiently. Gel treatments have been implemented as a cost-effective method to plug high permeability zones and thus improve sweep efficiency in reservoirs. However, when extensive cross-flows exist between formation layers, gel treatments become less efficient. Polymer was used in polymer flooding to increase the viscosity of the injected fluids and to correct the fingering problem. However, such treatment may be uneconomical since dramatic viscosity loss (80-90%) is caused by shearing degradation during the injection process near the wellbore.

This research …

Effect Of Particle Size And Trench Configuration On Deposition From Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Robert G. Laycock, Devin Rappleye, Thomas H. Fletcher

Faculty Publications

Particulate deposition experiments were performed in a turbine accelerated deposition facility to examine the effects of flyash particle size and trench configuration on deposits near film cooling holes. Deposition on two bare metal Inconel coupons was studied, with hole spacings (s/d) of 3.4 and 4.5. Two sizes of sub-bituminous coal ash particles were used, with mass mean diameter of 4 and 13 μm, respectively. The effect of a cooling trench at the exit of the cooling holes was also examined in this deposition facility. Experiments were performed at different angles of impaction. Particles were accelerated to a combustor exit flow …

Film Cooling Effectiveness And Heat Transfer Near Deposit-Laden Film Holes, Scott Lewis, Brett Barker, Jeffrey P. Bons, Weiguo Ai, Thomas H. Fletcher

Faculty Publications

Experiments were conducted to determine the impact of synfuel deposits on film cooling effectiveness and heat transfer. Scaled up models were made of synfuel deposits formed on film-cooled turbine blade coupons exposed to accelerated deposition. Three distinct deposition patterns were modeled: a large deposition pattern (maximum deposit peak = 2 hole diameters) located exclusively upstream of the holes, a large deposition pattern (maximum deposit peak = 1.25 hole diameters) extending downstream between the cooling holes, and a small deposition pattern (maximum deposit peak = 0.75 hole diameter) also extending downstream between the cooling holes. The models featured cylindrical holes inclined …

Investigation Of An Iron-Based Additive On Coal Pyrolysis And Char Oxidation At High Heating Rates, John M. Sowa, Thomas H. Fletcher

Faculty Publications

Iron-based catalysts have been shown to enhance coal pyrolysis and char oxidation at low to moderate temperatures and heating rates (b1250 K and 1–1000 K/s). Such catalytic activity has not been demonstrated at high heating rates and temperatures approaching pulverized coal combustion applications. The effect of an iron-based additive on coal pyrolysis and char combustion was studied in a flat-flame burner system at high particle heating rates using a Kentucky bituminous coal. Pyrolysis and char reactivity of two treated coals with different catalyst loadings were studied and compared with the untreated coal. The total volatiles yield for the treated coals …

Coal Swelling Model For High Heating Rate Pyrolysis Applications, Randy C. Shurtz, Kolbein K. Kolste, Thomas H. Fletcher

Faculty Publications

Thermal swelling of coal during pyrolysis strongly influences combustion and gasification rates. Coal swelling is known to vary strongly with coal rank, heating rate, and total pressure. New experiments confirm and clarify previous observations that maximum swelling occurs for high-rank bituminous coals at heating rates slightly below 10⁴ K/s. Advanced swelling models based on bubble physics yield good qualitative trends at low heating rates, but they fail to predict observed decreases in coal swelling as particle heating rates increase beyond 10⁴ K/s. An empirical swelling correlation for computational fluid dynamics (CFD) applications that correctly describes experimentally observed trends …

The Effects Of Wind On The Flame Characteristics Of Individual Leaves, Wesley J. Cole, Mckaye H. Dennis, Thomas H. Fletcher, David R. Weise

Faculty Publications

Individual cuttings from five shrub species were burned over a flat-flame burner under wind conditions of 0.75–2.80m s^-1. Both live and dead cuttings were used. These included single leaves from broadleaf species as well as 3 to 5 cm-long branches from coniferous and small broadleaf species. Flame angles and flame lengths were determined by semi-automated measurements of video images. Additional data, such as times and temperatures corresponding to ignition, maximum flame height and burnout were determined using video and infrared images. Flame angles correlated linearly with wind velocity. They also correlated with the Froude number when either the …

Studies Related To Coulombic Fissions Of Charged Droplets And Hygroscopic Behavior Of Mixed Particles, Harry Cook Hunter Iii

University of Kentucky Doctoral Dissertations

This dissertation describes two independent studies related to charged aerosols. The first study examines the role of electrical conductivity on the amounts of charge and mass emitted during the break-up of charged droplets via Coulombic fission. The second study examines the hygroscopic behavior of mixed particles. The results from both studies are presented here in detail along with an in-depth discussion of pertinent literature and applications in modern technologies.

Charged droplets break-up via a process termed Coulombic fission when their charge density reaches a certain level during which they emit a portion of their charge and mass in the form …

Evaluation Of The Physicochemical Properties And Stability Of Solid Lipid Nanoparticles Designed For The Delivery Of Dexamethasone To Tumors, Melissa Howard

University of Kentucky Doctoral Dissertations

Pre-clinical and clinical trials suggest that pre-treatment with dexamethasone (Dex) may facilitate enhanced uptake of subsequently administered chemotherapeutic agents. To reduce the side effects associated with systemic administration of Dex, solid lipid nanoparticles (SLNs) containing dexamethasone palmitate (Dex-P) were prepared as a means of achieving tumor-targeted drug delivery. These studies were aimed at evaluating the physicochemical properties and both the physiological and storage stability of the SLNs.

SLNs were prepared using nanotemplate engineering technology. Stearyl alcohol (SA) was used as the lipid phase with Brij^® 78 and Polysorbate 60 as surfactants and PEG6000 monostearate as a long-chain PEGylating agent. …

Implications Of Surface Runoff Recharge In Semi-Arid Regions On Groundwater Sustainability, Omar M. Al-Qudah

Open Access Theses & Dissertations

Amargosa Desert, Nevada regional groundwater studies show that the surface runoff infiltration occurring in the arroyos following runoff producing storms, and this infiltration is considered to be a major source of groundwater recharge. Groundwater infiltration through alluvium was investigated in the Amargosa Desert using borehole drill cuttings, groundwater chemistry, and applying a novel method for collecting runoff water. The sampling process included sediment, precipitation, and runoff water. In total, 176 runoff, 182 sediment, and 45 precipitation samples were collected between January, 2009 and January, 2011.Water chemistry, chloride concentrations, and stable isotopes of water collected from specially designed runoff samplers, placed …