Engineering Commons^™

Deagglomeration And Mixing Via The Rapid Expansion Of High Pressure And Supercritical Suspensions, Daniel To

Dissertations

Nano-materials are the focus of many research activities due to the desirable properties imparted from their small grain size and high interfacial surface area. However, these materials are highly cohesive powders in the dry state and typically form large agglomerates, leading to a diminished surface area or even grain growth, which minimizes the effectiveness of these nanomaterials. This dissertation addresses the issue of mixing nanopowders constituents by deagglomerating them and achieving simultaneous mixing so that even after inevitable reagglomeration, the effectiveness of large interfacial surface area may be preserved.

Nano-particle mixtures were prepared using the environmentally benign dry mixing methods …

Slides: Shale And Air Quality: The View From The Other Side, Jeremy Nichols

Shale Plays in the Intermountain West: Legal and Policy Issues (November 12)

Presenter: Jeremy Nichols, Climate & Energy Program Director, WildEarth Guardians, Denver, CO

18 slides

Effect Of Temperature Variation On The Magnetostrictive Properties Of Coalxfe2−Xo4, Ikenna C. Nlebedim, N. Ranvah, Y. Melikhov, P. I. Williams, J. E. Snyder, A. J. Moses, David C. Jiles

David C. Jiles

The effect of temperature variation on the magnetoelasticproperties of the CoAlxFe2−xO4 system (for x=0.0, 0.2, 05, and 0.7) has been studied. Substitution of Al3+ for Fe3+ was found to lower the Curie temperature of the samples and to change the lattice parameter. The magnitude of peak to peak magnetostriction, strain sensitivity, magnetomechanical hysteresis, and relative contributions of λ111 and λ100 to the resultant magnetostriction were found to vary with temperature. The results show the possibility of tailoring the magnetoelasticproperties of highly magnetostrictive cobalt ferrite at temperatures of interest by cation substitution.

Business Models For Commercial-Scale Carbon Dioxide Sequestration; With Focus On Storage Capacity And Enhanced Oil Recovery In Citronelle Dome, Richard A. Esposito

All ETDs from UAB

Fossil fuels, such as coal and natural gas, currently play an enormous role in our nation's base-load energy supply and provide reliable domestic energy security. If fossil fuels are to remain a component of future energy production in a carbon constrained world, then carbon-neutral energy options must be available. With fossil fuels, point-source environmental control technologies will be required to help comply with future carbon dioxide (CO2) emissions standards. One very promising technology, carbon capture and storage (CCS), consists of the separation of CO2 from the products of combustion of fossil fuels or from fuel gas produced by gasification of …

Slides: Environmentally Friendly Drilling Systems Program (Efd), Rich Haut

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center

23 slides

Reducing Greenhouse Gas Emissions By Inducing Energy Conservation And Distributed Generation From Elimination Of Electric Utility Customer Charges, Joshua M. Pearce, Paul J. Harris

Joshua M. Pearce

Demonstration Of Clean Particle Seeding For Particle Image Velocimetry In A Closed Circuit Supersonic Wind Tunnel, Charles M. Mcniel

Theses and Dissertations

The purpose of this research was to determine whether solid carbon dioxide (CO₂) particles might provide a satisfactory, and cleaner, alternative to traditional seed material for Particle Image Velocimetry (PIV) for use in a closed circuit supersonic wind tunnel. The Air Force Institute of Technology (AFIT) closed circuit pressure-vacuum supersonic wind tunnel was utilized, which achieves a nominal Mach number of Mach 2.9 in a 2.5 inch by 2.5 inch square test section. CO₂ was dispensed into the flow as a liquid from a standard compressed gas liquid tank through two different injector styles at two injection …

Particle Image Velocimetry Using A Novel, Non-Intrusive Particle Seeding, Charles J. Delapp Ii

Theses and Dissertations

The purpose of this research effort was to study the use of non-intrusive particle seeding for Particle Image Velocimetry (PIV). Current seeding material and techniques involve the use of either solid particles or liquid mixtures which can contaminate or damage closed circuit wind tunnels, and in some cases can introduce a potential fire or explosive hazard. The proposed method is based on creating seed particles utilizing Carbon Dioxide (CO2). The CO2 would be dispensed into the flow as a liquid, immediately condensing to solid seed particles as they leave the spray nozzle. The advantage of using these particles is that …

Co2-Selective Membranes Containing Amino Groups, W.S. Winston Ho

Chemical and Materials Engineering Faculty Patents

Novel compositions suitable for fabrication of CO₂-selective membranes are disclosed. In one aspect, the present invention is directed to compositions comprising polyimide/polyamine blends and copolymers, and to compositions comprising interfacially polymerized polyamides. In another aspect this invention is directed to novel CO₂-selective membranes comprising such polyimide/polyamine blends and copolymers, and to novel CO₂-selective membranes comprising interfacially polymerized polyamides. In yet another aspect, the present invention is directed to a novel water-gas-shift (WGS) reactor comprising the novel CO₂-selective membranes. Advantageously, the use of the novel CO₂-selective membrane allows alteration of the …

Screening Of Mgo- And Ceo2-Based Catalysts For Carbon Dioxide Oxidative Coupling Of Methane To C2+ Hydrocarbon, Istadi, Nor Aishah Saidina Amin

Istadi

The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM) have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based solids with oxides from alkali (Li2O), alkaline earth (CaO), and transition metal groups (WO3 or MnO). The presence of the peroxide (O2_2 ) active sites on the Li2O2, revealed by Raman spectroscopy, may be the key factor in the enhanced performance of some of the Li2O/MgO catalysts. The high reducibility of the CeO2 catalyst, an important factor in the CO2-OCM catalyst activity, may be enhanced by the presence of …

Dual-Pump Dual-Broadband Coherent Anti-Stokes Raman Scattering In Reacting Flows, Sukesh Roy, Terrence R. Meyer, Robert P. Lucht, Mikael Afzelius, Per-Erik Bengtsson, James R. Gord

Terrence R Meyer

A dual-pump, dual-broadband coherent anti-Stokes Raman scattering system for simultaneous measurements of temperature and concentrations of N2, O2, and CO2 in reacting f lows is demonstrated. In this system pure rotational transitions of N2 O2 and rovibrational transitions of N2 CO2 are probed simultaneously with two narrowband pump beams, a broadband pump beam, and a broadband Stokes beam. The main advantage of this technique is that it permits accurate temperature measurements at both low and high temperatures as well as concentration measurements of three molecules.

Mathematical Modeling And Applications For Concrete Carbonation, Ming-Te Liang, Shieng-Min Lin

Journal of Marine Science and Technology

A new concept, carbon dioxide (CO2) transport in concrete, is proposed in this paper to describe solute-transport processes. Using this concept, a new one-dimensional mathematical model was developed to describe the transport phenomena of carbon dioxide in concrete structures. By treating transport phenomena as a concrete carbonation process, a one-dimensional linear partial differential equation was derived based on the principle of mass balance and convective-dispersive equation and was found the analytical solution by the separation of variables and the Laplace transform methods combined with some substitution approaches. The concrete carbonation numerical results were determined using parameters, such as the diffusion …

Carbon Dioxide Capture From Flue Gas Using Regenerable Sodium-Based Sorbents, Ya Liang

LSU Master's Theses

The overall objective of this project is to develop a simple and inexpensive process to separate carbon dioxide (CO2) as an essentially pure stream from a fossil fuel combustion gases using a regenerable sodium-based sorbent. This objective of this phase of the project is to evaluate CO2 capture using sodium-based sorbents in single-cycle and multicycle tests as a function of calcination and carbonation conditions. The sorbent precursors investigated were sodium bicarbonates supplied by Church and Dwight, Inc., and natural trona supplied by Solvay. All precursors were first calcined to sodium carbonate and then converted to sodium bicarbonate (NaHCO3) or Wegscheider’s …

Mathematical Modeling And Prediction Method Of Concrete Carbonation And Its Applications, Ming Te Liang, Wenjun Qu, Chih-Hsin Liang

Journal of Marine Science and Technology

The carbonation process of concrete is principally a diffusion phenomenon. The penetration rate of carbon dioxide depends mainly on the concrete quality and the exposure condition. Based on both Fick’s first and second laws of linear diffusion equations, the threedimensional equation of conservation of mass is expressed. This equation can be reduced to two- and one- dimensional equations of conservation of mass which can predict the carbonation depth beneath corners and the general surface of concrete structures, respectively. The objectives of this investigation are to measure the depth of carbonation from the free surface of a concrete member and to …

The Development Of A Method To Extract High Purity Oxygen From The Martian Atmosphere, Dongchuan Wu

Mechanical & Aerospace Engineering Theses & Dissertations

A glow-discharge in an ambient Mars atmosphere (total pressure of 5 torr, composed of 95% carbon dioxide) results in the dissociation of carbon dioxide molecules into carbon monoxide and oxygen. If the glow-discharge zone is maintained adjacent and close to a silver membrane, operated at temperatures above 400°C, atomic and molecular oxygen, produced by the glow-discharge, can be separated from the other species by atomic diffusion through the membrane to an ultrahigh vacuum region where the desorbed O₂ is then collected. Experiments have been conducted to study the behavior of the glow discharge in both molecular oxygen and carbon …

The Development Of A Senior Unit Operations Laboratory On The Supercritical Extraction Of Solid Naphthalene With Supercritical Carbon Dioxide, Ronald G. Gabbard

Theses

A Senior level Undergraduate Unit Operations Laboratory experiment was developed for the extraction of Naphthalene with supercritical Carbon Dioxide. A Supercritical Extraction Screening System purchased from Autoclave Engineers of Erie, Pennsylvania was modified slightly for use as the laboratory equipment. The experiment consists of extracting solid naphthalene from a sand bed in a fixed bed extractor and determining the mass transfer coefficient for the unit.

The lab has been designed to allow the students to develop their own experimental plan without much direct input. The experimental outline provided for the students primarily focuses on information needed for safe and proper …

Crystal Structures Of N2o To 12 Gpa By X‐Ray Diffraction, R. L. Mills, Bart Olinger, D. T. Cromer, Richard Alan Lesar

Richard Alan Lesar

The structures and phase transitions of N2O were studied by powder x‐ray diffraction in a tungsten–carbide anvil device from about 100 to 300 K and 2 to 12 GPa. Two solid phases, α‐N2O and β‐N2O, were observed. The α pattern is consistent with the known low‐pressure low‐temperature ordered cubic form, space group Pa3, up to 4.8 GPa where transition to a new β solid occurs. From refinements using photographic x‐ray intensities, the β‐N2O structure was determined to be orthorhombic Cmca. There are four molecules in a unit cell with a=4.954 Å, b=4.497 Å, and c=6.201 Å at 5.81 GPa and …

A Study Of The Action Of Various Energizers In The Carburization Of Steel, William N. Warren

Bachelors Theses and Reports, 1928 - 1970

The object of casehardening is to produce articles of steel having a tough or ductile interior and a hard sur­face. Quenching produces a surface somewhat harder than the interior, but in order to obtain a high surface hard­ness, the percentage of alloying elements in the steel must be raised to such an extent that the core or central por­tion becomes hard and brittle also.