Chemical Engineering Commons^™

Solids Back-Mixing In Cfb-Furnaces, Filip Johnsson, David Pallarès

The 14th International Conference on Fluidization – From Fundamentals to Products

No abstract provided.

Coarse-Grained Models For Momentum, Energy And Species Transport In Gas-Particle Flows, Sankaran Sundaresan, Stefan Radl, Christian C. Milioli, Fernando E. Milioli

The 14th International Conference on Fluidization – From Fundamentals to Products

No abstract provided.

Bioreducible Polymer Nanosystems For Gene Delivery, Yi Zou

Wayne State University Dissertations

This dissertation describes the research of bioreducible polymers for gene delivery. A series of bioreducible poly(amido amine)s (PAAs) were synthesized. They complex with DNA forming polyplex nanoparticles and layer-by-layer (LbL) thin films as gene delivery vectors. Atomic force microscope (AFM), especially in situ real time AFM, provides a microscopic view of DNA release dynamics. It is shown that the depolymerization of bioreducible polymer triggers DNA release via disulfide-thiol exchange reaction. The AFM images revealed a three-stage pathway beginning with a morphological change from metastable nanostructures into the more favorable toroid structure. Then toroids interact with each other by aggregation and …

Green Diesel Production Via Catalytic Hydrogenation/Decarboxylation Of Triglycerides And Fatty Acids Of Vegetable Oil And Brown Grease, Elvan Sari

Wayne State University Dissertations

Increase in the petroleum prices, projected increases in the world’s energy demand and environmental awareness have shifted the research interest to the alternative fuel technologies. In particular, green diesel, vegetable oil/animal fat/waste oil and grease derived hydrocarbons in diesel boiling range, has become an attractive alternative to biodiesel— a mixture of fatty acid methyl esters, particularly due to its superior fuel properties that are similar to petroleum diesel. Hence, green diesel can be used as a drop-in fuel in the current diesel engines. The current technology for production of green diesel– hydrodeoxygenation of triglycerides and fatty acids over conventional hydrotreating …

Minimum-Mass Panels Under Probabilistic Aeroelastic Flutter Constraints, Bret Stanford, Philip Beran

United States Air Force: Publications

Aeroelastic flutter is a dangerous failure mode, and aircraft structural components are designed under a deterministic flutter margin. Meeting this safety factor may result in overly-conservative structures, however, an alternative approach incorporates uncertainties into the computational models, and imposes a maximum allowable flutter probability during the optimization process. This technique is demonstrated for the variable-thickness design of an elastic panel subjected to supersonic flow. A performance measure approach based on the first -order reliability method incorporates probabilistic flutter constraints during the search for a minimum-mass panel. Optimization results are given for uncertainties in the panel's boundary conditions, and for non-deterministic …

Multi-Scale Characterization Of Nanostructured Sodium Aluminum Hydride, Shathabish Narasegowda

Doctoral Dissertations

Complex metal hydrides are the most promising candidate materials for onboard hydrogen storage. The practicality of this class of materials is counter-poised on three critical attributes: reversible hydrogen storage capacity, high hydrogen uptake/release kinetics, and favorable hydrogen uptake/release thermodynamics. While a majority of modern metallic hydrides that are being considered are those that meet the criteria of high theoretical storage capacity, the challenges lie in addressing poor kinetics, thermodynamics, and reversibility. One emerging strategy to resolve these issues is via nanostructuring or nano-confinement of complex hydrides. By down-sizing and scaffolding them to retain their nano-dimensions, these materials are expected to …

How Atomic Level Interactions Drive Membrane Fusion: Insights From Molecular Dynamics Simulations, Navendu Bhatnagar

Wayne State University Dissertations

This project is focused on identifying the role of key players in the membrane fusion process at the atomic level with the use of molecular dynamics simulations. Membrane fusion of apposed bilayers is one of the most fundamental and frequently occurring biological phenomena in living organisms. It is an essential step in several cellular processes such as neuronal exocytosis, sperm fusion with oocytes and intracellular fusion of organelles to name a few. Membrane fusion is a frequent process in a living organism but is still not fully understood at the atomic level in terms of the role of various factors …

Polymeric Nanocarriers And Their Oral Inhalation Formulations For The Regional Delivery Of Nucleic Acids To The Lungs, Denise Santos Conti

Wayne State University Dissertations

Gene therapy has attracted attention in the fields of medicine, pharmacy, and bionanotechnology due to the potential for treating a large number of medically relevant diseases. Oral inhalation (OI) is a promising route for the administration of therapeutics, including small molecules and biomacromolecules, such as nucleotides, peptides, and proteins, to (locally) and through (systemically) the lungs. The use of OI is especially attractive for the delivery of nucleic acids as it provides a direct and non-invasive route for targeting the lungs. Pressurized metered-dose inhalers (pMDIs), are the most commonly used OI in treatment of lung diseases and are thus promising …

Engineering Nanoparticle And Nanoring Patterns For The Study Of Molecular Crystallization Under Nanoconfinement, Sunxi Wang

Wayne State University Dissertations

This dissertation focuses on generating the inorganic nanoparticle/organic nanorod hybrid nanostructures by the strategy of nanoparticle induced molecular crystallization developed by us and the new electrochemical method. We synthesize the gold nanoparticles with different sizes and functional groups and then fabricate the nanohybrids with fatty acid nanorods by spin coating method. Atomic force microscope monitors the topography of the hybrid nanostructures to help understand the underlying mechanism of the crystallization process. This successful self-assembled method could be used to fabricate nanohybrids based on seed-mediated nucleation. Also the novel "nano-flasks" have been generated by particle lithography method, which could be served …

Adiabatic Flame Temperature For Combustion Of Methane Ii, Rebeca Pupo

Undergraduate Journal of Mathematical Modeling: One + Two

We calculate the adiabatic flame temperature of a mixture of methane and oxygen in the presence of a diluent gas then determine the mole fractions of methane without respect to nitrogen and solve for the moles of oxygen present. Knowing the moles of methane and oxygen, allows us to calculate the moles of nitrogen present at four constant mole fractions of nitrogen, and the adiabatic flame temperature is determined from the energy released by the reaction. Lastly, we produce several graphs to compare the adiabatic flame temperatures at different mole fractions of nitrogen.

Microfluidic Devices Applied On Enriching Post –Translational Modified Proteins For Proteomics, Hui Xia

Doctoral Dissertations

In this work, microfluidic devices were developed for enriching post-translational modified proteins. Post-translational modifications (PTM) of proteins play essential roles in cellular physiology and disease. The identification of protein substrates and detection of modification site helps understand PTM-mediated regulation in essential biological pathways and functions in various diseases. However, PTM proteins are typically present only at trace levels, making them difficult to identify in mass spectrometry based proteomics. This work study is about the design, fabrication and testing of the microfluidic device for the enrichment of abundant amount of PTMs. Carbonylated protein is used as a representative PTM to illustrate …

Studying On Capacity Fade Mechanisms Of Li-Ion Batteries Through Modeling, Yiling Dai

Theses and Dissertations

Li-ion batteries are promising candidates as power sources for hybrid electric/electric vehicles, as well as storage devices for renewable energies (wind, solar). Longer life batteries are more desirable for large-scale application, which would help lower the capital cost ($/KW) and improve the system stability. However, the aging problem of Li-ion batteries obstructs their fast penetration into these markets. The cell life can be improved based on an in-depth understanding of the fade mechanisms. The purpose of this dissertation is to explore, through a mathematical modeling approach, failure mechanisms of Li-ion batteries.

To study the capacity fade of a LiMn2O4 (LMO) …

Modeling Of Biorefinery Supply Chain Economic Performance With Discrete Event Simulation, Joseph S. Amundson

Theses and Dissertations--Manufacturing Systems Engineering

As competition for fossil fuels accelerates, alternative sources of chemicals, fuels, and energy production become more appealing to researchers and the layman. Among the candidates to fill this growing niche is lignocellulosic biomass. Many researchers have examined supply chain design and optimization for biofuel and bioenergy production throughout the years. However, these models often fail to capture the variability and uncertainty inherent to the biomass supply chain. Multiple factors with high degrees of stochasticity can have major impacts on the performance of a biorefinery: weather, biomass quality, feedstock availability, and market demand for products are just a few. To begin …

Nanoscale Metal Oxide And Supported Metal Catalysts For Li-Air Battery, Kan Huang

Doctoral Dissertations

"The dissertation work focuses on research and development of durable nanoscale catalysts and supports for rechargeable Li-air batteries that use aqueous catholytes. Transition metal oxides, TiO₂ and Nb₂O₅ in particular, were prepared from a sol-gel process in the form of nanocoatings (5~50 nm) on carbon nanotubes (CNTs) and studied as catalyst supports. Carbon doping in the oxides and post annealing significantly increased their electronic conductivity. Pt catalyst on the support with TiO₂ (Pt/c-TiO₂/CNTs) showed a much better oxygen reduction reaction (ORR) activity than a commercial Pt on carbon black (Pt/C). Negligible loss ( …

Scaleup And Hydrodynamics Study Of Gas-Solid Spouted Beds, Shreekanta Basavaraj Aradhya

Doctoral Dissertations

"A thorough understanding of the complex flow structure of gas-solid spouted bed is crucial for design, scale-up and performance. Advanced gas-solid optical probes were developed and used to evaluate different hydrodynamic parameters of spouted beds. These optical probes measure solids concentration, velocity and their time series fluctuations. Since solids concentration needs to be converted to solids holdup through calibration, for meaningful interpretation of results, a novel calibration method was proposed (which is inexpensive and reliable compared to the current reported methods) and validated in the present study. The reported dimensionless groups approach of spouted bed scale-up was assessed and was …

Effect Of Dense Heat Exchanging Internals On The Hydrodynamics Of Bubble Column Reactors Using Non-Invasive Measurement Techniques, Mohammed Khloofh Al Mesfer

Doctoral Dissertations

"Given their efficiency and capital cost reduction, bubble/slurry bubble column reactors are the reactors of choice for Fischer-Tropsch (FT) synthesis, offering clean alternative fuels and chemicals. FT synthesis is an exothermic process that requires many heat exchanging tubes in order to remove heat efficiently and maintain the desired temperature and isothermal operating condition. The impact of the heat exchanging tubes (internals) on the hydrodynamics is not fully understood. Reliably designing and scaling up bubble column reactors requires proper understanding of hydrodynamics, as well as heat and mass transfer parameters.

The main objective of this work is to advance the understanding …

Minimizing Formation Damage For Preformed Particle Gels Treatment In Mature Reservoirs, Mahmoud Omran Elsharafi

Doctoral Dissertations

"This research studied the effect of preformed particle gels (PPGs) on unswept, low-permeable zones/areas. The objective was to find methods that minimized the damage caused by PPGs on unswept, low-permeable zones/areas, thus improving PPG treatment efficiency. These results can help to identify of the best PPG types, particle sizes, and brine concentrations for specific reservoirs and treatments. This study used sandstone core samples with various degrees of permeability. Two types of particle gels, a strong Daqing gel (DQ) and a weak Liquiblock™ 40k gel (40K), were used, each with a different strength.

This research included two stages. Firstly, both a …

Behavior And Effects Of Nanoparticles In Complex Fluid Systems, Chen Wang

Doctoral Dissertations

"The development of nanoscale technologies has greatly expanded the scientific and engineering horizons and also has the potential to turn molecular discoveries into worldwide benefits on multiple fronts. Despite recent extensive efforts, the focus of nanoparticle studies has been on their synthesis and various possible derivatives. In this dissertation, molecular based modeling and simulation studies have been performed to characterize and understand the behavior, properties, and effects of nanoparticles in some important material systems. The results show that small nanoparticles that are highly faceted have significant shape effects, which are not captured by classical continuum-based approaches. When dissolved in confined …

Partial Oxidation Of Ethane To Acetic Acid On Titania Supported Movnbpd Catalyst, Yousef S. Al-Zeghayer, Abdulrhman S. Al-Awadi, Baba Y. Jibril, Moustafa A. Soliman, Sulaiman Al-Mayman

Chemical Engineering

Partial oxidation of ethane was studied on unsupported and supported Mo-V-Nb oxides. Different grades of titania (Crystal-AF4.60, AF7.70 and AF12.5 and Degussa P25) were explored as supports. Samples of the catalyst were characterized using XRD, SEM and BET surface area. The reaction was carried out at 200-275°C and 200 psi. At ethane conversion (6%), unsupported samples exhibited selectivities to ethylene and acetic acid of 76 and 23%, while for Degussa P25-supported sample, the values were 54 and 35%, respectively. Addition of Pd (0.196%) led to an increase in selectivity to acetic acid of 75%.

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use the lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales, to simplify the analysis of coating film dynamics. We study the dynamics of coating thin films on horizontal stationary and rotating cylinders in general, and when the effect of van der Waals forces is significant. A computer code based on the method of orthogonal collocation is developed and is used for the study of the instabilities of coating thin film flow on cylinders to identify conditions of stable operation. For stationary cylinders, the equations are symmetric and the …

Characterization And Aerosol Dispersion Performance Of Spray-Dried Chemotherapeutic Pegylated Phospholipid Particles For Dry Powder Inhalation Delivery In Lung Cancer, Samantha A. Meenach, Kimberly W. Anderson, J. Zach Hilt, Ronald J. Mcgarry, Heidi M. Mansour

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Pulmonary inhalation chemotherapeutic drug delivery offers many advantages for lung cancer patients in comparison to conventional systemic chemotherapy. Inhalable particles are advantageous in their ability to deliver drug deep in the lung by utilizing optimally sized particles and higher local drug dose delivery. In this work, spray-dried and co-spray dried inhalable lung surfactant-mimic PEGylated lipopolymers as microparticulate/nanoparticulate dry powders containing paclitaxel were rationally designed via organic solution advanced spray drying (no water) in closed-mode from dilute concentration feed solution. Dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine poly(ethylene glycol) (DPPE-PEG) with varying PEG chain length were mixed with varying amounts of paclitaxel in methanol …

Potential For Electrical Power Generation Using Forest Wood Biomass In Rural Areas Of Catalonia, Arnau Gonzalez

Open Access Theses

Biomass is a renewable energy source that has been used for many years. However, its usage as an electricity source in Spain is not well developed due to many causes, among which highlights the lack of knowledge about the available technical potential. This research sought to close this gap assessing the technical potential for electricity generation using forest wood biomass in rural areas of Catalonia. The study characterizes the amount and type of biomass available in Catalonian forests that can be used to produce electricity without going beyond the capacity of regeneration of the forest, as well as the state-of-the-art …

Properties Of Peg, Ppg And Their Copolymers Influence On The Gap-Fill Characteristics Of Damascene Interconnects, Kevin Ryan

Legacy Theses & Dissertations (2009 - 2024)

A laboratory scale plating cell was built that provided reproducible bottom-up fill results for the electrochemical deposition of copper in damascene features. Several techniques used in the full wafer plating tool were incorporated into the setup to accurately control the process conditions. These techniques included but were not limited to a voltage controlled `hot-entry' step, a custom coupon holder to allow sample rotation, a secondary thief electrode and an automatic entry system. The results of qualification experiments are presented to demonstrate that precise control was realized along with repeatable partial fill plating results. The qualified setup was then used to …

Parsing The Effects Of Physical Microenvironmental Cues On Stem Cell Adhesion And Lineage Specification, Greg M. Harris

Theses and Dissertations

Tissue engineering is a broad field geared toward improving or replacing biological material and comprises an immense collection of biological nuances to consider before strategies for clinical applications can be fully realized. Physical and biochemical signals are responsible for making up a cell's microenvironment to guide morphology and function through cell-extracellular matrix signaling, cell-cell signaling, and soluble signaling. In particular, a deeper understanding of these cell-extra cellular matrix factors guiding stem cell adhesion, spreading, and differentiation is crucial to harnessing the potential to develop tissue for regenerative purposes. Mounting evidence suggests that physical cues are a key to understanding the …

Coal Char-Co2 Gasification Measurements And Modeling In A Pressurized Flat-Flame Burner, Randy C. Shurtz, Thomas H. Fletcher

Faculty Publications

A pressurized flat-flame burner (PFFB) was used to conduct coal gasification studies. The PFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ∼105 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. Char gasification studies by CO2 were conducted on a subbituminous coal and 4 bituminous coals in the PFFB. Pressures of 5, 10, and 15 atm were used with gas compositions of 20, 40, and 90 mol % CO2. Gas conditions with peak …

Comparison Of A Particle Filter And Other State Estimation Methods For Prognostics Of Lithium-Ion Batteries, Eric Alan Walker

Theses and Dissertations

A particle filter (PF) is shown to be more accurate than non-linear least squares (NLLS) and an unscented Kalman filter (UKF) for predicting the remaining useful life (RUL) and time until end of discharge voltage (EODV) of a Lithium-ion battery. The three algorithms track four states with correct initial guesses and 5% variation on the initial guesses. The more accurate prediction performance of PF over NLLS and UKF is reported for three Lithium-ion battery models: a data-driven empirical model, an equivalent circuit model, and a physics-based single particle (SP) model.

Gelation Characteristics And Osteogenic Differentiation Of Stromal Cells In Inert Hydrolytically Degradable Micellar Polyethylene Glycol Hydrogels, Danial Barati

Theses and Dissertations

The use of polyethylene glycol (PEG) hydrogels in tissue engineering is limited by their persistence in the site of regeneration. In an attempt to produce degradable PEG-based hydrogels while preserving the unique properties of PEG, linear (LPELA) and star (SPELA) poly(ethylene glycol-co-lactide) acrylate, star (SPEDA) poly(ethylene glycol-co-dioxanone), star (SPEGA) poly(ethylene glycol-co-glycolide) acrylate as the least hydrophobic and (SPECA) poly(ethylene glycol-co-caprolactone) as the most hydrophobic macromonomers with short hydrophobic segments were synthesized. The hydrogels were characterized with respect to gelation time, modulus, water content, sol fraction, degradation, and osteogenic differentiation of encapsulated marrow stromal cells (MSCs). Chain extension of PEG with …

The Effect Of Bi-Polar Plate And Membrane Materials On Water Transport In Pemfcs, Visarn Lilavivat

Theses and Dissertations

An analysis of liquid water transport and removal in Proton Exchange Membrane Fuel Cells (PEMFCs) as affected by different membranes and the geometry and surface roughness of bipolar plates on is presented. Four topics are considered. First, the channel dimension and shape of various flow fields have been shown to affect the cell performance and the uniformity in the distributions of current. Typical variations in the channel width, height, and undercut that may occur with manufactured metal plates are studied. These sample-to-sample variations and distributions are studied and compared with laboratory-scale graphite plates. The goal of the work is to …

New Approach For Modeling Hybrid Pressure Swing Adsorption-Distillation Processes, Fan Wu

Theses and Dissertations

A new methodology for modeling hybrid pressure swing adsorption (PSA)-distillation processes has been developed. Two hybrid systems were simulated as examples. One is for ethanol dehydration, and the other is for propane/propylene separation. Firstly, a distillation process simulator such as Chemsep was used to simulate the distillation process of the hybrid system, in which the PSA unit was treated as a "black box" with an assumed process performance. In this way, a hybrid PSA-distillation process can be analyzed simply by performing mass balances around these units and running Chemsep to determine the possibility of energy saving compared to a reference …