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Full-Text Articles in Chemical Engineering

Determination Of Phase Equilibria And The Critical Point Using Two-Phase Molecular Dynamics Simulations With Monte Carlo Sampling, Sonal Patel Jun 2012

Determination Of Phase Equilibria And The Critical Point Using Two-Phase Molecular Dynamics Simulations With Monte Carlo Sampling, Sonal Patel

Theses and Dissertations

The two-phase MD technique employed in this work determines the liquid and vapor phase densities from a histogram of molecular densities within phase clusters in the simulation cell using a new Monte Carlo (MC) sampling method. These equilibrium densities are then fitted in conjunction with known critical-point scaling laws to obtain the critical temperature, and the critical density. This MC post-processing method was found to be more easily implemented in code, and it is efficient and easily applied to complex, structured molecules. This method has been successfully applied and benchmarked for a simple Lennard-Jones (LJ) fluid and a structured molecule, …


Chemical Potential Perturbation: A Method To Predict Chemical Potential Using Molecular Simulations, Stan G. Moore Jun 2012

Chemical Potential Perturbation: A Method To Predict Chemical Potential Using Molecular Simulations, Stan G. Moore

Theses and Dissertations

A new method, called chemical potential perturbation (CPP), has been developed to predict the chemical potential as a function of composition in molecular simulations. The CPP method applies a spatially varying external potential to the simulation, causing the composition to depend upon position in the simulation cell. Following equilibration, the homogeneous chemical potential as a function of composition can be determined relative to some reference state after correcting for the effects of the inhomogeneity of the system. The CPP method allows one to predict chemical potential for a wide range of composition points using a single simulation and works for …


A New Assessment Method To Easily Identify Areas Needing Improvement In Course-Level Learning Outcomes, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle Jun 2012

A New Assessment Method To Easily Identify Areas Needing Improvement In Course-Level Learning Outcomes, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle

Faculty Publications

A New Assessment Method to Easily Identify Areas Needing Improvement Course‐level Learning Outcomes Thomas A. Knotts IV, W. Vincent Wilding, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University Assessment of student proficiency in expected outcomes, whether on the course or program level, is an important aspect of curriculum development in engineering programs. The reasons for such assessment range from desires to improve student learning to fulfilling requirements of various accreditation bodies. But regardless of the reasons, the challenge is to develop suitable metrics which can clearly identify areas which need improvement. In order to …


Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle Jun 2012

Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle

Faculty Publications

Developing and Assessing Leadership in Engineering Students W. Vincent Wilding, Thomas A. Knotts IV, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University The Ira A. Fulton College of Engineering and Technology at Brigham Young University is focusing on five initiatives: Leadership, Innovation, Global Awareness, Character, Technical Excellence. Efforts in the realm of leadership include freshmen leadership seminars and a required sophomore course entitled Global Leadership in a Technological World. Departments within the college are expected to build on this foundation in the junior and senior years. The Chemical Engineering Department has developed an effective …


Mobility Of A Semiflexible Chain Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman Jun 2012

Mobility Of A Semiflexible Chain Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman

Faculty Publications

The classic results of de Gennes and Odijk describe the mobility of a semiflexible chain confined in a nanochannel only in the limits of very weak and very strong confinement, respectively. Using Monte Carlo sampling of the Kirkwood diffusivity with full hydrodynamic interactions, we show that the mobility of a semiflexible chain exhibits a broad plateau as a function of extension before transitioning to an Odijk regime, and that the width of the plateau depends on the anisotropy of the monomers. For the particular case of DNA in a high ionic strength buffer, which has highly anisotropic monomers, we predict …


Fiber Optic Monitoring Of Subsea Equipment, David Brower, John Hedengren, Cory Loegering, Alexis Brower, Karl Witherow, Karl Winter Jun 2012

Fiber Optic Monitoring Of Subsea Equipment, David Brower, John Hedengren, Cory Loegering, Alexis Brower, Karl Witherow, Karl Winter

Faculty Publications

Bass Lite deepwater field in the Gulf of Mexico, at water depths of approximately 2,050 m (6,750 feet), commenced operation in February 2008. Natural gas is produced from Bass Lite via a 90-km (56-mile) subsea tieback to the Devils Tower Spar. This project involved several innovations, one of which was the incorporation of a fiber optic sensing system that measures realtime temperature, pressure and strain along the pipeline length. This is a first of its kind innovation that is in actual operation.


Uv Visible Spectra Analysis Of High Temperature Water Gas Shift Catalysts Made From Iron, Lanthanum, Copper, And Chromium Oxides, Jared C. Brown May 2012

Uv Visible Spectra Analysis Of High Temperature Water Gas Shift Catalysts Made From Iron, Lanthanum, Copper, And Chromium Oxides, Jared C. Brown

Theses and Dissertations

Hydrogen is a vital component in several different chemical reactions as well as a potential fuel source for the future. The water gas shift (WGS) reaction converts CO and water to hydrogen and CO2. The objective of this work is to first, characterize the potential benefits of the addition of lanthanum oxide (lanthana) to the iron-chromium-copper (Fe-Cr-Cu) oxide catalysts industrially used in high temperature water gas shift processes, and second, analyze these catalysts using in-situ UV-Visible spectroscopy. The benefits of each component in the catalyst are discussed as well as potential benefits from the addition of lanthana. Lanthana is a …


A Pressure Gauge Based On Gas Density Measurement From Analysis Of The Thermal Noise Of An Atomic Force Microscope Cantilever, Dongjin Seo, Mark R. Paul, Willian A. Ducker May 2012

A Pressure Gauge Based On Gas Density Measurement From Analysis Of The Thermal Noise Of An Atomic Force Microscope Cantilever, Dongjin Seo, Mark R. Paul, Willian A. Ducker

Faculty Publications

We describe a gas-density gauge based on the analysis of the thermally-driven fluctuations of an atomic force microscope (AFM) cantilever. The fluctuations are modeled as a ring-down of a simple harmonic oscillator, which allows fitting of the resonance frequency and damping of the cantilever, which in turn yields the gas density. The pressure is obtained from the density using the known equation of state. In the range 10–220 kPa, the pressure readings from the cantilever gauge deviate by an average of only about 5% from pressure readings on a commercial gauge. The theoretical description we use to determine the pressure …


Mesh Adaption For Efficient Multiscale Implementation Of One-Dimensional Turbulence, D. O. Lignell, A. R. Kerstein, G. Sun, E. I. Monson Apr 2012

Mesh Adaption For Efficient Multiscale Implementation Of One-Dimensional Turbulence, D. O. Lignell, A. R. Kerstein, G. Sun, E. I. Monson

Faculty Publications

One-Dimensional Turbulence (ODT) is a stochastic model for turbulent flow simulation. In an atmospheric context, it is analogous to single-column modeling (SCM) in that it lives on a 1D spatial domain, but different in that it time advances individual flow realizations rather than ensemble-averaged quantities. The lack of averaging enables a physically sound multiscale treatment, which is useful for resolving sporadic localized phenomena, as seen in stably stratified regimes, and sharp interfaces, as observed where a convective layer encounters a stable overlying zone. In such flows, the relevant scale range is so large that it is beneficial to enhance model …


One-Dimensional-Turbulence Simulation Of Flame Extinction And Reignition In Planar Ethylene Jet Flames, David O. Lignell, Devin Rappleye Apr 2012

One-Dimensional-Turbulence Simulation Of Flame Extinction And Reignition In Planar Ethylene Jet Flames, David O. Lignell, Devin Rappleye

Faculty Publications

A series of three simulations of temporally evolving, planar, nonpremixed ethylene jet flames are performed using the one-dimensional-turbulence (ODT) model. The simulations are performed at a fixed Reynolds number, but varying Damköhler numbers, under conditions that result in significant flame extinction and reignition. Results are compared to corresponding direct numerical simulations (DNSs), which exhibit 40, 70, and nearly 100% peak flame extinction among the three cases. The planar, temporal configuration is ideal for comparison and validation of the ODT model, and identical thermodynamic, transport, and kinetic models were used. The ODT model captures the jet evolution and heat …


Chemical Potential Perturbation: Extension Of The Method To Lattice Sum Treatment Of Intermolecular Potentials, Stan G. Moore, Dean R. Wheeler Apr 2012

Chemical Potential Perturbation: Extension Of The Method To Lattice Sum Treatment Of Intermolecular Potentials, Stan G. Moore, Dean R. Wheeler

Faculty Publications

The recently developed chemical potential perturbation (CPP) method [S. G. Moore and D. R. Wheeler, J. Chem. Phys. 134, 114514 (2011) https://doi.org/10.1063/1.3561865.] is extended to the lattice (Ewald) sum treatment of intermolecular potentials. The CPP method predicts chemical potentials for a range of composition points using the local (position-dependent) pressure tensor of an inhomogeneous system. When computing the local pressure tensor, one can use the Irving-Kirkwood (IK) or Harasima (H) contours of distributing the pressure. We compare these two contours and show that for a planar interface, the homogeneous pressure and resulting chemical potential can be approximated with …


Multi-Processor Computation Of Thrombus Growth And Embolization In A Model Of Blood-Biomaterial Interaction Based On Fluid Dynamics, Brandon Thomas Andersen Apr 2012

Multi-Processor Computation Of Thrombus Growth And Embolization In A Model Of Blood-Biomaterial Interaction Based On Fluid Dynamics, Brandon Thomas Andersen

Theses and Dissertations

This work describes the development and testing of a real-time three-dimensional computational fluid dynamics simulation of thrombosis and embolization to be used in the design of blood-contacting devices. Features of the model include the adhesion and aggregation of blood platelets on device material surfaces, shear and chemical activation of blood platelets, and embolization of platelet aggregates due to shear forces. As thrombus develops, blood is diverted from its regular flow field. If shear forces on a thrombus are sufficient to overcome the strength of adhesion, the thrombus is dislodged from the wall. Development of the model included preparing thrombosis and …


Simulations Of Controlled Fires Using The One-Dimensional Turbulence Model With Application To Fire Spread In Wildland Fires, Elizabeth Ida Monson Apr 2012

Simulations Of Controlled Fires Using The One-Dimensional Turbulence Model With Application To Fire Spread In Wildland Fires, Elizabeth Ida Monson

Theses and Dissertations

The mechanism of flame propagation in fuel beds of wildland fires is important to understand and quantify fire spread rates. Fires spread by radiative and convective heating and often require direct flame contact to achieve ignition. The flame interface in an advancing fire is unsteady and turbulent, making study of intermittent flames in complex fuels difficult. This thesis applies the one-dimensional turbulence (ODT) model to a study of flame propagation by simulating a lab-scale fire representative of the flame interface in a fuel bed and incorporating solid fuel particles into the ODT code. The ODT model is able to resolve …


Resolution Limit For Dna Barcodes In The Odijk Regime, Yanwei Wang, Wes F. Reinhart, Douglas R. Tree, Kevin D. Dorfman Jan 2012

Resolution Limit For Dna Barcodes In The Odijk Regime, Yanwei Wang, Wes F. Reinhart, Douglas R. Tree, Kevin D. Dorfman

Faculty Publications

We develop an approximation for the probability of optically resolving two fluorescent labels on the backbone of a DNA molecule confined in a nanochannel in the Odijk regime as a function of the fluorescence wavelength, channel size, and the properties of the DNA (persistence length and effective width). The theoretical predictions agree well with equivalent data produced by Monte Carlo simulations of a touching wormlike bead model of DNA in a high ionic strength buffer. Although the theory is only strictly valid in the limit where the effective width of the nanochannel is small compared with the persistence length of …


Effect Of Hole Spacing On Deposition Of Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Elizabeth Bonsignore, Jeffrey P. Bons Jan 2012

Effect Of Hole Spacing On Deposition Of Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Elizabeth Bonsignore, Jeffrey P. Bons

Faculty Publications

Particulate deposition experiments were performed in a turbine accelerated deposition facility to examine the nature of flyash deposits near film cooling holes. Deposition on both bare metal and thermal barrier coating (TBC) coupons was studied, with hole spacing (s/d) of 2.25, 3.375, and 4.5. Sub-bituminous coal ash particles (mass mean diameter of 13 microns) were accelerated to a combustor exit flow Mach number of 0.25 and heated to 1183°C before impinging on a target coupon. The particle loading in the 1 h tests was 310 ppmw. Blowing ratios were varied in these experiments from 0 to 4.0 with the density …


Computational Analysis Of Conjugate Heat Transfer And Particulate Deposition On A High Pressure Turbine Vane, Weiguo Ai, Thomas H. Fletcher Jan 2012

Computational Analysis Of Conjugate Heat Transfer And Particulate Deposition On A High Pressure Turbine Vane, Weiguo Ai, Thomas H. Fletcher

Faculty Publications

Numerical computations were conducted to simulate flash deposition experiments on gas turbine disk samples with internal impingement and film cooling using a computational fluid dynamics (CFD) code (FLUENT). The standard k-epsilon turbulence model and Reynoldsaveraged Navier–Stokes were employed to compute the flow field and heat transfer. The boundary conditions were specified to be in agreement with the conditions measured in experiments performed in the BYU turbine accelerated deposition facility (TADF). A Lagrangian particle method was utilized to predict the ash particulate deposition. Userdefined subroutines were linked with FLUENT to build the deposition model. The model includes particle sticking/rebounding and particle …


Deposition Near Film Cooling Holes On A High Pressure Turbine Vane, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Scott Lewis, Jeffrey P. Bons Jan 2012

Deposition Near Film Cooling Holes On A High Pressure Turbine Vane, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Scott Lewis, Jeffrey P. Bons

Faculty Publications

Deposition on film-cooled turbine components was studied in an accelerated test facility. The accelerated deposition facility seeds a natural-gas burning combustor with finely ground coal ash particulate at 1180 C and 180 m/s (M=0.25). Both cylindrical and shaped holes, with and without thermal barrier coating, were studied over a range of blowing ratios from 0.5 to 4.0. Coolant density ratios were maintained at values from 2.1 to 2.4. Deposition patterns generated with the cylindrical film cooling holes indicated regions of low deposition in the path of the coolant with heightened deposition between film holes. This distinctive pattern was more accentuated …


Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter Jan 2012

Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter

Faculty Publications

A generalized model for describing the pyrolysis behavior of low-grade fuels is being developed for incorporation into larger combustion simulation models. Light gas and tar yields from black liquor or biomass pyrolysis can be predicted using the chemical percolation devolatilization (CPD) model originally developed for coal. The initial approach is to measure the average chemical structures in a black liquor sample using 13C NMR spectroscopy. These chemical structures are then used in pyrolysis model predictions. With few changes from the coal-derived kinetic parameters, the model describes the organic pyrolysis behavior of black liquor samples obtained in a nitrogen-purged furnace. It …


Coal Swelling Model For Pressurized High Particle Heating Rate Pyrolysis Applications, Randy C. Shurtz, Joseph W. Hogge, Kade C. Fowers, Gregory S. Sorensen, Thomas H. Fletcher Jan 2012

Coal Swelling Model For Pressurized High Particle Heating Rate Pyrolysis Applications, Randy C. Shurtz, Joseph W. Hogge, Kade C. Fowers, Gregory S. Sorensen, Thomas H. Fletcher

Faculty Publications

A model was previously developed to describe the decrease in swelling during coal pyrolysis at atmospheric pressure when maximum particle heating rates increase from 104 K/s to 105 K/s. That model included effects of coal type using chemical structure properties. This paper presents results of new experiments to study the effects of elevated pressure and high heating rates on coal pyrolysis. A pressurized flat-flame burner (PFFB) was designed and built to conduct these studies. The pyrolysis experiments reported in this paper were conducted at particle heating rates of ∼105 K/s and maximum gas temperatures of 1700 to 1900 …


A Cfd Model For Thermal Conversion Of Thermally Thick Biomass Particles, Ramin Mehrabian, Selma Zahirovic, Robert Scharler, Ingwald Obernberger, Stefan Kleditzsch, Siegmar Wirtz, Victor Scherer, Hong Lu, Larry L. Baxter Dec 2011

A Cfd Model For Thermal Conversion Of Thermally Thick Biomass Particles, Ramin Mehrabian, Selma Zahirovic, Robert Scharler, Ingwald Obernberger, Stefan Kleditzsch, Siegmar Wirtz, Victor Scherer, Hong Lu, Larry L. Baxter

Faculty Publications

A one-dimensional model for the thermal conversion of thermally thick biomass particles is developed for the simulation of the fuel bed of biomass grate furnaces. The model can be applied for cylindrical and spherical particles. The particle is divided into four layers corresponding to the main stages of biomass thermal conversion. The energy and mass conservation equations are solved for each layer. The reactions are assigned to the boundaries. The model can predict the intra-particle temperature gradient, the particle mass loss rate as well as the time-dependent variations of particle size and density, as the most essential features of particle …


Critical And Phase-Equilibrium Properties Of An Ab Initio Based Potential Model Of Methanol And 1-Propanol Using Two-Phase Molecular Dynamics Simulations, Sonal Patel, W. Vincent Wilding, Richard L. Rowley Dec 2011

Critical And Phase-Equilibrium Properties Of An Ab Initio Based Potential Model Of Methanol And 1-Propanol Using Two-Phase Molecular Dynamics Simulations, Sonal Patel, W. Vincent Wilding, Richard L. Rowley

Faculty Publications

Two-phase molecular dynamics simulations employing a Monte Carlo volume sampling method were performed using an ab initio based force field model parameterized to reproduce quantum-mechanical dimer energies for methanol and 1-propanol at temperatures approaching the critical temperature. The intermolecular potential models were used to obtain the binodal vapor-liquid phase dome at temperatures to within about 10 K of the critical temperature. The efficacy of two all-atom, site-site pair potential models, developed solely from the energy landscape obtained from high-level ab initio pair interactions, was tested for the first time. The first model was regressed from the ab initio landscape without …


Chemical Templating By Afm Tip-Directed Nano-Electrochemical Patterning, Kyle A. Nelson Dec 2011

Chemical Templating By Afm Tip-Directed Nano-Electrochemical Patterning, Kyle A. Nelson

Theses and Dissertations

This work has examines the creation and use of chemical templates for nanocircuit and other nanodevice fabrication. Chemical templating can be useful in attachment, orientation and wiring of molecularly templated circuits. DNA origami provides a suitable method for creating molecularly templated circuits as DNA can be folded into complex shapes and functionalized with active circuit elements, such as semiconducting nanomaterials. Surface attachment of DNA origami structures can be accomplished by hybridization of dangling single-stranded DNA (ssDNA) on the origami structures with complementary surface-bound strands. Chemical templating provides a pathway for placing the patterned surface-bound attachment points needed for surface alignment …


Modeling Solid Propellant Ignition Events, Daniel A. Smyth Dec 2011

Modeling Solid Propellant Ignition Events, Daniel A. Smyth

Theses and Dissertations

This dissertation documents the building of computational propellant/ingredient models toward predicting AP/HTPB/Al cookoff events. Two computer codes were used to complete this work; a steady-state code and a transient ignition code Numerous levels of verification resulted in a robust set of codes to which several propellant/ingredient models were applied. To validate the final cookoff predictions, several levels of validation were completed, including the comparison of model predictions to experimental data for: AP steady-state combustion, fine-AP/HTPB steady-state combustion, AP laser ignition, fine-AP/HTPB laser ignition, AP/HTPB/Al ignition, and AP/HTPB/Al cookoff. A previous AP steady-state model was updated, and then a new AP …


Selective Deposition Of Metallic And Semiconductor Materials Onto Dna Templates For Nanofabrication, Jianfei Liu Nov 2011

Selective Deposition Of Metallic And Semiconductor Materials Onto Dna Templates For Nanofabrication, Jianfei Liu

Theses and Dissertations

This work examines the selective deposition of metallic and semiconductor materials onto DNA templates for the fabrication of nanodevices. DNA origami provides a simple and robust method for folding DNA into a variety of shapes and patterns and makes it possible to create the complex templates needed for nanodevices, such as nanoelectronic circuits, plasmonics, and nanosensors. Metallization of DNA origami templates is essential for the fabrication of such nanodevices. In addition, selective deposition of semiconductor materials onto the DNA template is of importance for making many nanodevices such as nanocircuits. Metallization of DNA origami presents several challenges beyond those associated …


Surface Modification Of Liposomes Containing Nanoemulsions, Jonathan Michael Hartley Nov 2011

Surface Modification Of Liposomes Containing Nanoemulsions, Jonathan Michael Hartley

Theses and Dissertations

Many attempts have been made to make cancer therapy more selective and less detrimental to the health of the patients. Nanoparticles have emerged as a way to solve some of the problems of traditional chemotherapy. Nanoparticles can provide protection for the therapeutic from degradation or clearance, as well as protection to healthy tissue from the damaging effects of chemotherapy drugs. Researchers are pursuing different strategies but all have the same goals of improving the outcomes of cancer patients. The field of controlled release of drugs has increased significantly in hopes of better treating diseases like cancer. Improved control of drug …


Analysis Of Coal By Static Time-Of-Flight Secondary Ion Mass Spectrometry (Tof-Sims), Lei Pei, Guilin Jiang, Larry Lin Baxter, Matthew R. Linford Nov 2011

Analysis Of Coal By Static Time-Of-Flight Secondary Ion Mass Spectrometry (Tof-Sims), Lei Pei, Guilin Jiang, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Coal remains a primary fuel for power generation. Herein we present time-of-flight secondary ion mass spectra (ToF-SIMS data) taken with a Ga primary ion beam from ca. 30 coal specimens. These commercially different coal specimens were obtained from coal mining companies and/or power plants. They represent all major coal types used in power generation (bituminous coals, subbituminous coals, and lignites), and include low-rank materials (lignites and subbituminouscoals), which are represented as a minor portion of the data. Often, inorganic ions (Na, Al, Si,and K) are pronounced in the spectra, overshadowing peaks from organic moieties. This reflectsthe high sensitivity of SIMS …


Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan Oct 2011

Supported Monoethanolamine For Co2 Separation, Morris D. Argyle, Zhuoyan Sun, Maohong Fan

Faculty Publications

An alternative method for using monoethanolamine (MEA) in CO2 separation is developed from the viewpoints of the MEA-CO2 reaction environment and the process of spent sorbent regeneration. The method could be used to considerably reduce energy consumption compared to conventional aqueous MEA processes. MEA-TiO2 (MT) CO2 sorbent is synthesized using pure MEA and a support material, TiO2. The performance of the MT sorbent on CO2 separation was investigated in tubular reactors under various experimental conditions. The effects of several major factors on CO2 sorption by the MT sorbent were investigated. The sorption capacity of the MT sorbent increased with MEA …


Effects Of Pressure On The Properties Of Coal Char Under Gasification Conditions At High Initial Heating Rates, Randy C. Shurtz Sep 2011

Effects Of Pressure On The Properties Of Coal Char Under Gasification Conditions At High Initial Heating Rates, Randy C. Shurtz

Theses and Dissertations

The effects of elevated pressure and high heating rates on coal pyrolysis and gasification were investigated. A high-pressure flat-flame burner (HPFFB) was designed and built to conduct these studies. The HPFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ~10^5 K/s, pressures of up to 15 atm, and gas temperatures of up to 2000 K. Residence times were varied from 30 to 700 ms in this study. Pyrolysis experiments were conducted at particle heating rates of ~10^5 K/s and maximum gas temperatures of ~1700 K at pressures of 1 to 15 atm. …


Phospholipid Transport In Silicon Hydrogel Contact Lenses, Yibei Zhao Sep 2011

Phospholipid Transport In Silicon Hydrogel Contact Lenses, Yibei Zhao

Theses and Dissertations

Dry eye syndrome has been associated with the lack of phospholipids in the tear film, leading to disruption of the tear film and subsequent irritation. Characterization of the transport and release of phospholipids from a silicone hydrogel contact lens is required to assess the possible use of these lenses for phospholipid delivery to increase patient comfort. This thesis examines the use of silicone hydrogel contact lenses as phospholipid delivery devices. Contact lenses of silicone hydrogel composition were loaded with varying amounts of radiolabeled 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) from a solution of n-propanol. These lenses were eluted at 35°C into artificial …


Optimizing The Use Of Ultrasound To Deliver Chemotherapeutic Agents To Cancer Cells From Polymeric Micelles, Ghaleb A. Husseini, Nabil M. Abdel-Jabbar, Farouq S. Mjalli, William G. Pitt, Ala'a Al-Mousa Sep 2011

Optimizing The Use Of Ultrasound To Deliver Chemotherapeutic Agents To Cancer Cells From Polymeric Micelles, Ghaleb A. Husseini, Nabil M. Abdel-Jabbar, Farouq S. Mjalli, William G. Pitt, Ala'a Al-Mousa

Faculty Publications

In this study, we present an artificial neural network (ANN) model that attempts to predict the dynamic release of doxorubicin (Dox) from P105 micelles under different ultrasonic power densities at 20 kHz. The goal is to utilize the developed ANN model in optimizing the ultrasound application to achieve a target drug release at the tumor site by controlling power density and ultrasound duration via an ANN-based model predictive control. The parameters of the controller are then tuned to achieve good reference signal tracking.