Chemical Engineering Commons^™

Continuous Monitoring Of Bioactive Glass Conversion Using Optical Biosensors, Prajakta Bhagwat

Masters Theses

"The engineered regeneration of bone is a significant challenge being undertaken to treat conditions such as traumatic casualties, bone cancer, osteoporosis, etc. Advances in hard tissue regrowth may potentially lead to significantly improved lives for millions of people. Bioactive glasses as potential materials in the fabrication of scaffolds for hard tissue regeneration have been studied recently. Bone regrowth requires maintenance of optimal levels of oxygen, glucose, phosphate, calcium, and pH. Current work at Missouri S & T's Center for Bone and Tissue Repair and Restoration focuses on developing optical biosensors to monitor: conversion of bioactive glass to hydroxyapatite, ease of …

Mesh Optimization Of Finite Element Models Of Wellbore Stress Analysis, Ming-Yen Lee

Masters Theses

"Numerical modeling methods such as the widely used finite element method provide an excellent opportunity to analyze the wellbore state of stress for a variety of applications such as wellbore integrity, wellbore design or hydraulic fracturing. However, numerical modeling methods introduce errors by nature and may not precisely match the analytical solution if the meshing of the numerical model is not carefully taken care of. This study presents a parametric study of the meshing parameters mesh density, element type, and model size for 2-dimensional and 3-dimensional vertical wellbore models under three different types of boundary conditions, and a guideline for …

Characterization Of Thermal And Mechanical Properties Of Polypropylene-Based Composites For Fuel Cell Bipolar Plates And Development Of Educational Tools In Hydrogen And Fuel Cell Technologies, Daniel López Gaxiola

Dissertations, Master's Theses and Master's Reports - Open

In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack, circulates the gases that participate in the electrochemical reaction within the fuel cell and allows for removal of the excess heat from the system.

The materials fabricated in this work were tested to determine their mechanical and thermal properties. These materials were produced by adding varying amounts of single carbon …

Production Of Biofuel Intermediates From Woody Feedstocks Via Fast Pyrolysis And Torrefaction, Jordan Lee Klinger

Dissertations, Master's Theses and Master's Reports - Open

The main objective of this research was to investigate pyrolysis and torrefaction of forest biomass species using a micropyrolysis instrument. It was found that 30-45% of the original sample mass remained as bio-char in the pyrolysis temperature range of 500 - 700˚C for aspen, balsam, and switchgrass. The non-char mass was converted to gaseous and vapor products, of which 10-55% was water and syngas, 2-12% to acetic acid, 2-12% to hydroxypropanone, 1-3% to furaldehyde, and 5-15% to various phenolic compounds. In addition, several general trends in the evolution of gaseous species were indentified when woody feedstocks were pyrolyzed. With increasing …

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 …

Pyrolysis Kinetics Of A Green River Oil Shale Using A Pressurized Tga, James L. Hillier, Thomas H. Fletcher

Faculty Publications

Crushed samples of Green River Oil Shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000 C. Two to four mass release peaks were observed with the major two corresponding to kerogen pyrolysis and carbonate decomposition. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). An F-test was used to determine confidence regions and compare the kinetic parameters among the oil shale and demineralized samples, between the two pressure levels, and between the models. The …

Fourier Transform Emission Spectroscopy Of Yh And Yd: Observation Of New A¹Δ And B¹Π Electronic States, R. S. Ram, G. Li, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

The emission spectra of YH and YD molecules have been investigated in the 3600–12 000 cm⁻¹ region using a Fourier transform spectrometer. Molecules were formed in an yttrium hollow cathode lamp operated with a continuous flow of a mixture of Ne and Ar gases, and YH and YD were observed together in the same spectra. A group of bands observed near 1 μm have been identified as 0-0 and 1-1 bands of the A¹Δ-X¹Σ⁺ and B¹Π-X¹Σ⁺ transitions of YH and the 0-0 bands of the same two transitions …

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. …

Analytical Design Method For Cold Production Of Heavy Oil With Bottom Water Using Bilateral Sink Wells, Wenting Qin

LSU Doctoral Dissertations

Few heavy oil reservoirs with strong bottom water drives have been developed successfully because of severe water coning. Water coning tends to cause low ultimate recovery, low well productivity, and high water production. Although thermal and gravity-assisted methods might improve recovery in oil reservoirs, such methods are widely perceived as either economically unfavorable or technologically infeasible. This study proposes a new, cold production technique, called Bilateral Water Sink (BWS), to meet those challenges. The BWS method suppresses water cresting by producing oil and water simultaneously from separate, horizontal wells completed in the oil and water zones; the oil and water …

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 …

The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements. Characterization revealed each material to be amorphous with a T_g in the region of 650-660°C. The network connectivity decreased (1.83-1.35) with the addition of TiO₂ which was also evident with analysis by X-ray photoelectron spectroscopy. Ion release from cements were determined using atomic absorption spectroscopy for zinc (Zn^₂₊), calcium (Ca^₂₊), strontium (Sr^₂₊), Silica (Si^₄₊) and titanium (Ti4+). Ions such as Zn^₂₊ (0.1-2.0 mg/l), Ca²⁺ (2.0-8.3 mg/l,) Sr²⁺ (0.1-3.9 mg/l), and S^{i4+ …}

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 …

Modeling Small Molecule Elution From A Hydrogel Using A Microfluidic Technique, Stephanie Evans

Master’s Theses

Drug release from a fluid-contacting biomaterial is simulated using a microfluidic device with channels defined by solute-loaded hydrogel. In order to mimic a drug delivery device, a solution of poly(ethylene glycol) diacrylate (PEG-DA), solute, and photoinitiator is cured inside a microfluidic device with a channel through the center ofthe hydrogel. As water is pumped through the channel, solute diffuses out of the hydrogel and into the water. Channel sizes within the devices range from 300 µm to 1000 µm to simulate vessels within the body. The properties of the PEG hydrogel were characterizedby the extent of crosslinking, the swelling ratio, …

Investigation Of The Hygroscopic And Morphological Properties Of Atmospheric Aerosols, Laura Cook

Master’s Theses

The first objective of this thesis was to examine the hygroscopic and morphological nature of various substances through the use of an Environmental Scanning Electron Microscope (ESEM). The hygroscopic growth and changes in morphology for pure-component aerosols were studied for particles greater than 2 µm in size. Hygroscopic growth was observed through changes in relative humidity (RH) and hygroscopic growth curves were created. The second objective of this thesis, the hygroscopic growth of multi-component aerosol mixtures, was studied using Hygroscopic Tandem Differential Mobility Analysis(HTDMA). The size distribution for an aerosol stream was determined before and after the stream was subjected …

Synthesis And Surface Modification Of Cdse And Cds Quantum Dots Exhibiting High Quantum Yield, Jeweliet Yost

Master’s Theses

The thesis investigates the effect of surface treatment with various reducing and oxidizing agents on the quantum yield (QY) of CdSe and CdS quantum dots (QDs). The QDs, as synthesized by the organometallic method, contained defect sites on their surface that trapped photons and prevented their radiative recombination, therefore resulting in adecreased QY. To passivate these defect sites and enhance the QY, the QDs were treated with various reducing and oxidizing agents, including: sodium borohydride (NaBH4), calcium hydride (CaH2), hydrazine (N2H4), benzoyl peroxide (C14H10O4), and tert-butylhydroperoxide (C4H10O2). It was hypothesized that the reducing/oxidizing agents reduced the ligands on the QD …

An Investigation Of Two Ceramic Electron Conductors For Use In Solid Oxide Fuel Cell Anodes, Ian Hasson

Master’s Theses

Conducted work with two potential alternatives to Ni, La0.8Sr0.2Cr0.5Mn0.5 (LSCM) and Sr doped LaVO3 (LSV) to serve as the electron conductor in the anode of solid oxide fuel cells SOFCs.

Photocatalytic Destruction Of Halogenated Organic Compounds In Water With A New Photocatalyst, Mabruka Hadidan

Open Access Theses & Dissertations

In this research, a newly developed high surface area semiconductor porous material was synthesized from potassium titanium niobium mixed oxide (KTiNbO5) to be used as a photo catalyst in the presence of UV light to degrade halogenated organic compounds in water. The goal of the project was to investigate the catalytic activity of the material for its effectiveness in the degradation of the halogenated organic compounds, and it is the first investigation of this new photocatalyst with halogenated compounds. Model compounds dichloromethane, 1-chlorobutane, chlorobenzene, and trifluoroacetic acid in aqueous solutions were tested with the photocatalyst under ultraviolet light irradiation, using …

Molecular Dynamics Of Ionic Liquids In Nanoporous Electrodes, Nav Nidhi Rajput

LSU Master's Theses

Molecular dynamics simulations were performed to investigate the structural and dynamical properties of ionic liquid (IL) [EMIM+][TFMSI-] confined inside slit-like graphite pores. ILs are salts composed of an organic cation and an organic or inorganic anion with melting point below 100ºC. Their unique properties such as great thermal and chemical stability have gained them immense attention in recent years. The main goal of this research is to understand how molecular level properties of ILs are affected by the properties of the nanoporous materials. The results obtained in this work indicate that pore size has a profound effect on structural and …

A Study Of A Smog-Fog-Smog Cycle And The Processing Of Pah And Oxy-Pah By A Fog Cloud, Kalindi Pramod Khadapkar

LSU Master's Theses

Fog is a multiphase dynamic system which can provide a setting for various physicochemical processes affecting the fate of various organic pollutants such as polycyclic aromatic hydrocarbons (PAH) and their oxygenated forms (oxy-PAH) in the atmosphere. This study focuses on the processing of PAH and oxy-PAH during a smog-fog-smog cycle. Two field campaigns were carried out during the winters of year 2010 and year 2011 in the Central Valley of California, sampling two fog events in Fresno and five fog events in Davis. To study the transformations and distributions of PAH and oxy-PAH, different atmospheric species (fog water, gas phase, …

Evaluation Of Simultaneous Water And Gas Injection Using Co2, Shrinidhi Shetty

LSU Master's Theses

Miscible CO2 injection is the second largest contributor to global enhanced oil recovery, as it has successfully undergone extensive laboratory tests and field applications for recovering residual oil left behind after waterflooding. Prolific incremental recoveries have been obtained for some fields. Although miscible CO2 injections generally have excellent microscopic displacement efficiency they often result in poor sweep efficiency. In order to address sweep problems and maximize recoveries, other schemes of gas injection have been developed. Two such processes are water-alternating-gas (WAG) and simultaneous water-and-gas (SWAG) injection. WAG and SWAG have been successfully used to minimize poor sweep. Improved gas utilization …