Chemical Engineering Commons^™

Biodegradable Magnesium Alloys For Biomedical Implants: Properties, Challenges, And Surface Modifications With A Focus On Orthopedic Fixation Repair, Kevin Koshy Thomas, Mah Noor Zafar, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Biomedical devices made from high-modulus and hardness materials play a critical role in enhancing the quality of life for people with bone-related ailments. While these materials have been successfully used in orthopedic applications, concerns including stress-shielding have necessitated the exploration of alternative solutions. An ideal biomedical implant requires a delicate balance of mechanical performance, corrosion resistance, tissue biocompatibility, and other properties such as tribological performance and osseointegration. This review explores the suitability of biodegradable magnesium (Mg) alloys as a promising material for biomedical implants. It delves into the essential properties of biomedical implants, emphasizing the importance of matching mechanical characteristics …

Coarsening Dynamics Of Ternary Polymer Solutions With Mobility And Viscosity Contrasts, Jan Ulric Garcia, Douglas R. Tree, Alyssa Bagoyo, Tatsuhiro Iwama, Kris T. Delaney, Glenn H. Fredrickson

Faculty Publications

Using phase-field simulations, we investigate the bulk coarsening dynamics of ternary polymer solutions undergoing a glass transition for two models of phase separation: diffusion only and with hydrodynamics. The glass transition is incorporated in both models by imposing mobility and viscosity contrasts between the polymer-rich and polymer-poor phases of the evolving microstructure. For microstructures composed of polymer-poor clusters in a polymer-rich matrix, the mobility and viscosity contrasts significantly hinder coarsening, effectively leading to structural arrest. For microstructures composed of polymer-rich clusters in a polymer-poor matrix, the mobility and viscosity contrasts do not impede domain growth; rather, they change the transient …

Equation-Based And Data-Driven Modeling: Open-Source Software Current State And Future Directions, Lagrande Gunnell, Bethany Nicholson, John Hedengren

Faculty Publications

A review of current trends in scientific computing reveals a broad shift to open-source and higher-level programming languages such as Python and growing career opportunities over the next decade. Open-source modeling tools accelerate innovation in equation-based and data-driven applications. Significant resources have been deployed to develop data-driven tools (PyTorch, TensorFlow, Scikit-learn) from tech companies that rely on machine learning services to meet business needs while keeping the foundational tools open. Open-source equation-based tools such as Pyomo, CasADi, Gekko, and JuMP are also gaining momentum according to user community and development pace metrics. Integration of data-driven and principles-based tools is emerging. …

A Novel Application Of Spinning Disk Technology To Collect Plasma From Whole Blood Prior To Quantifying Plasma Rna, Naomi Rapier-Sharman, Mae-Lynn L. Hutchinson, Carlos M. Moreno, Abraham Quaye, Brian D. Poole, K. Scott Weber, William G. Pitt, Brett E. Pickett

Faculty Publications

The spinning disk technology has previously been utilized to isolate bacterial components from blood in hours instead of days. We hypothesized that this platform could be applied as an alternative approach to isolating plasma RNA from a whole blood sample. We consequently tested the efficacy of the spinning disk technology to extract plasma from whole blood upstream of RNA isolation and analysis. To do so, we collected plasma using either the spinning disk or the typical two-spin centrifuge method. We found that the spinning disk method results in significantly more hemolysis during collection than the conventional two-spin centrifuge method. However, …

Neutronic Analysis Of The Byu Molten Salt Micro Reactor, Collin Bradford, Edward Mercado, Braden Clayton, Lagrande Gunnell, Andrew Larsen, Matthew Memmott

Faculty Publications

Background: With the rising need for reliable and clean energy, researchers at Brigham Young University created a molten salt microreactor (MSMR) concept to help meet the world’s growing energy demands. The MSMR is rated at 45 MWth and is uniquely capable of passively dissipating all decay heat using conduction only.

Methods: This work presents the results of the simulated neutronic behavior of the MSMR using the Monte Carlo neutronics code OpenMC with the ENDF/B-VII.1 cross-section library at steady state conditions. The specific characteristics discussed in this work are: keff, power profile, axial and radial peak power factors, Doppler coefficient of …

Streamlining The Detection Of Human Thyroid Receptor Ligand Interactions With Xl1-Blue Cell-Free Protein Synthesis And Beta-Galactosidase Fusion Protein Biosensors, J. Porter Hunt, Tyler J. Free, Jackelyn Galiardi, Kevin M. Watt, David W. Wood, Bradley Charles Bundy

Faculty Publications

Thyroid receptor signaling controls major physiological processes and disrupted signaling can cause severe disorders that negatively impact human life. Consequently, methods to detect thyroid receptor ligands are of great toxicologic and pharmacologic importance. Previously, we reported thyroid receptor ligand detection with cell-free protein synthesis of a chimeric fusion protein composed of the human thyroid receptor beta (hTRβ) receptor activator and a β-lactamase reporter. Here, we report a 60% reduction in sensing cost by reengineering the chimeric fusion protein biosensor to include a reporter system composed of either the full-length beta galactosidase (β-gal), the alpha fragment of β-gal (β-gal-α), or a …

A Probabilistic View Of Protein Stability, Conformational Specificity, And Design, Jacob A. Stern, Tyler J. Free, Kimberlee L. Stern, Spencer Gardiner, Nicholas A. Dalley, Bradley Charles Bundy, Joshua L. Price, David Wingate, Dnnis Della Corte

Faculty Publications

Various approaches have used neural networks as probabilistic models for the design of protein sequences. These "inverse folding" models employ different objective functions, which come with trade-offs that have not been assessed in detail before. This study introduces probabilistic definitions of protein stability and conformational specificity and demonstrates the relationship between these chemical properties and the p(stucture|seq) Boltzmann probability objective. This links the Boltzmann probability objective function to experimentally verifiable outcomes. We propose a novel sequence decoding algorithm, referred to as “BayesDesign”, that leverages Bayes’ Rule to maximize the p(stucture|seq) objective instead of the p(seq|structure) objective common in inverse folding …

Recent Breakthroughs In Using Quantum Dots For Cancer Imaging And Drug Delivery Purposes, Aisha Hamidu, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Cancer is one of the leading causes of death worldwide. Because each person’s cancer may be unique, diagnosing and treating cancer is challenging. Advances in nanomedicine have made it possible to detect tumors and quickly investigate tumor cells at a cellular level in contrast to prior diagnostic techniques. Quantum dots (QDs) are functional nanoparticles reported to be useful for diagnosis. QDs are semiconducting tiny nanocrystals, 2–10 nm in diameter, with exceptional and useful optoelectronic properties that can be tailored to sensitively report on their environment. This review highlights these exceptional semiconducting QDs and their properties and synthesis methods when used …

Bacterial Extraction And Concentration From Blood Through Filtration Processes, Ryan L. Wood, Rebecca Prymak, Evelyn Welling, Alayna Bedwell, Jordan T. Wood, Damian E. Teasley, Magdalena Crofts, Hope Callister Anderson, Clifton M. Anderson, W Cameron Beard, Jacob Stepan, Alexandra Carter, William G. Pitt

Faculty Publications

Blood stream infections (BSIs) are challenging to rapidly and precisely diagnose. Current clinical diagnostic methods for BSI identification require culturing the blood sample for many hours prior to identifying the bacteria and possible antibiotic resistance. Removing the culturing step from the bacterial identification process of a BSI provides a significant reduction in the processing time, but shifts the rate-limiting step from the growth time to the concentration procedure, since CFU levels in clinical blood samples can be as low as 10 CFU/mL in blood. This study developed a novel whole blood filtration method to concentrate bacteria from a BSI without …

Transferrin-Targeted Liposomes In Glioblastoma Therapy: A Review, Paul Kawak, Nour M Al Sawaftah, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Glioblastoma (GBM) is a highly aggressive brain tumor, and its treatment is further complicated by the high selectivity of the blood–brain barrier (BBB). The scientific community is urgently seeking innovative and effective therapeutic solutions. Liposomes are a promising new tool that has shown potential in addressing the limitations of chemotherapy, such as poor bioavailability and toxicity to healthy cells. However, passive targeting strategies based solely on the physicochemical properties of liposomes have proven ineffective due to a lack of tissue specificity. Accordingly, the upregulation of transferrin receptors (TfRs) in brain tissue has led to the development of TfR-targeted anticancer therapeutics. …

Recommended Separation Distances For 1.3 Ammunition And Explosives, Clint Guymon, Ming Liu, Josephine Covino

Faculty Publications

Separation Distances are used throughout the world to protect people and assets from the potential hazardous effects from propellants, explosives, and pyrotechnics. The current separation distances for Hazard Division (HD) 1.3 substances and articles used in the United States, in some cases, may not adequately protect against the effects from heat flux and debris when those substances and articles are ignited in a confined structure. Multiple tests in such a confined scenario with HD 1.3 substances have shown that the heat flux and debris hazards could result in injury at distances beyond the current specified explosives safety separation distance (ESSD). …

Simultaneous Multistep Transformer Architecture For Model Predictive Control, Junho Park, Mohammad Reza Babaei, Samuel Arce Munoz, Ashwin N. Venkat, John Hedengren

Faculty Publications

Transformer neural networks have revolutionized natural language processing by effectively addressing the vanishing gradient problem. This study focuses on applying Transformer models to time-series forecasting and customizing them for a simultaneous multistep-ahead prediction model in surrogate model predictive control (MPC). The proposed method showcases improved control performance and computational efficiency compared to LSTM-based MPC and one-step-ahead prediction models using both LSTM and Transformer networks. The study introduces three key contributions: (1) a new MPC system based on a Transformer time-series architecture, (2) a training method enabling multistep-ahead prediction for time-series machine learning models, and (3) validation of the enhanced time …

Determination Of A Surrogate For Plutonium Electrorefining, Greg Chipman, Bryant Johnson, Suhee Choi, Chao Zhang, Michael Simpson, Devin Rappleye

Faculty Publications

Conducting research experiments on plutonium electrorefining is difficult due to the significant hazards and regulations associated with nuclear materials. Finding a surrogate for plutonium electrorefining studies would enable more fundamental research to be conducted. Potential surrogates were first identified by determining the physical properties required to conduct electrorefining at the same conditions commonly used in plutonium electrorefining, a molten metal and molten CaCl₂ at 1123 K. Ce-CeCl₃, In-InCl₃, and Pb-PbCl₂ were the only potential surrogates identified using these constraints. Sn-SnCl₂ was also tested at these same conditions. More potential surrogates were identified by …

Liposomes For The Treatment Of Brain Cancer—A Review, Richu Raju, Waad H. Abuwatfa, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Due to their biocompatibility, non-toxicity, and surface-conjugation capabilities, liposomes are effective nanocarriers that can encapsulate chemotherapeutic drugs and facilitate targeted delivery across the blood–brain barrier (BBB). Additionally, strategies have been explored to synthesize liposomes that respond to internal and/or external stimuli to release their payload controllably. Although research into liposomes for brain cancer treatment is still in its infancy, these systems have great potential to fundamentally change the drug delivery landscape. This review paper attempts to consolidate relevant literature regarding the delivery to the brain using nanocarriers, particularly liposomes. The paper first briefly explains conventional treatment modalities for cancer, followed …

A Review On Membrane Fouling Prediction Using Artificial Neural Networks (Anns), Waad H. Abuwatfa, Nour Al Sawaftah, Naif Darwish, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Membrane fouling is a major hurdle to effective pressure-driven membrane processes, such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). Fouling refers to the accumulation of particles, organic and inorganic matter, and microbial cells on the membrane’s external and internal surface, which reduces the permeate flux and increases the needed transmembrane pressure. Various factors affect membrane fouling, including feed water quality, membrane characteristics, operating conditions, and cleaning protocols. Several models have been developed to predict membrane fouling in pressure-driven processes. These models can be divided into traditional empirical, mechanistic, and artificial intelligence (AI)-based models. Artificial neural networks …

A Multi-Scale Method For Combined Design And Dispatch Optimization Of Nuclear Hybrid Energy Systems Including Storage, Daniel Hill, Dawson Mccrea, An Ho, Matthew Memmott, Kody Powell, John Hedengren

Faculty Publications

Reliable, carbon-free power generation is increasing in importance. Nuclear-renewable hybrid energy systems (NHES) are a potential solution for current generation challenges, but design and dispatch optimization for these systems remains challenging particularly when stochastic effects, long time horizons and nonlinear modeling are needed. This work presents a multi-scale method for combining the design and dispatch optimization problems for nonlinear NHES over long time horizons. Rather than treating the entire horizon as a single optimization problem, a large number of combined optimization problems are solved for shorter samples of the horizon resulting in distributions of optimal capacities for each of the …

Bringing The Analysis Of Electrodeposition Signals In Voltammetry Out Of The Shadows, Devin Rappleye, Ranon G. Fuller

Faculty Publications

Voltammetry studies of electrodeposition are growing rapidly. Yet, relations for the analysis of electrodeposition reactions in voltammetry remain relatively obscure in the literature. The existing cyclic and square wave voltammetry relations for electrodeposition and their limitations are discussed to increase awareness. A retrospective analysis is performed to demonstrate the impact of model selection in improving the analysis of electrodeposition behavior with voltammetric data. A repository for voltammetry models of electrodeposition is proposed to further increase familiarity and application of the most appropriate models, which would support a rapidly growing area of research and technological development.

Nonsolvent-Induced Phase Separation Inside Liquid Droplets, Rami Alhasan, Tanner A. Wilcoxson, Dakota S. Banks, Sion Jung, Douglas R. Tree

Faculty Publications

Nonsolvent-induced phase separation (NIPS) is a popular method for creating polymeric particles with internal microstructure, but many fundamental questions remain surrounding the kinetics of the complex coupled mass transfer and phase separation processes. In this work, we use simulations of a phase-field model to examine how (i) finite domain boundaries of a polymer droplet and (ii) solvent/nonsolvent miscibility affect the NIPS process. To isolate the effects of phase separation kinetics and solvent/nonsolvent mass transfer on the NIPS process, we study two different cases. First, we investigate droplet concentrations that originate inside the two-phase region, where phase separation kinetics alone governs …

Hierarchical, Porous Hydrogels Demonstrating Structurally Dependent Mechanical Properties, Elisabeth Lloyd, Rami Alhasan, Sujata Dhakal, Svetlana Morozova, Douglas R. Tree, Robert Hickey

Faculty Publications

While hierarchical ordering is a distinctive feature of natural tissues and is directly responsible for their diverse and unique properties, research efforts to synthesize biomaterials have primarily focused on using molecular-based approaches without considering multiscale structure. Here, we report a bottom-up self-assembly process to produce highly porous hydrogels that resemble natural tissues both structurally and mechanically. Randomly oriented, physically crosslinked nanostructured micelles form the walls of aligned, polymer-rich pore walls that surround water-rich cavities. Extremely soft elastic modulus (<  1 kPa), highly stretchability (greater than 12-times), strain-hardening, and completely reversible deformation result from the hierarchical structure. Independent control of nano and macroscales is realized through the combination of polymer macromolecular parameters and processing conditions, directly impacting the resulting phase behavior. Here, we demonstrate precise control of the material structure and structure orientation over many orders of magnitude (e.g., nm – µm), and reveal how the multiscale structure directly impacts mechanical properties.

Design And Performance Of A Laboratory Scale Pressurized Oxy-Coal Reactor, Scott Gardner, Cody Carpenter, Jacob Tuia, Aaron Skousen, Dustin Badger, Sandra Thomas, Bradley R. Adams, Dale R. Tree, Andrew R. Fry

Faculty Publications

A pressurized oxy-coal (POC) reactor has been designed, built and tested to investigate key technologies related to oxy-coal combustion including a dry coal feed system, an oxy-coal burner, and a slagging ash management system. The coal feed system utilized a fluidized bed to convey pulverized coal with CO2 from a coal bed into the reactor. The reactor has diagnostic capabilities including optical access, embedded thermocouples, fuel and gas flow rates, exhaust gas analysis (CO2, CO, NO, O2) and heat flux. At 13.6 atm and a firing rate of 89 kWth a mean feed rate of 12.5 kg/h was …

Semi-Differentiation Of Reversible, Soluble-Insoluble Potential Sweep Voltammograms, Tyler Williams, Ranon Fuller, Cameron Vann, Devin Rappleye

Faculty Publications

Semi-differentiation, or convolution as it is sometimes known, is a mathematical technique commonly used to disentangle overlapping peaks in cyclic or linear sweep voltammograms. However, this technique is often misapplied due to misunderstandings of fractional calculus. Additionally, rigorous treatment and validation of the theory of semi-differential analysis of reversible, soluble-insoluble electrochemical reactions is lacking. Peculiarities of semi-differentiation are explored; theoretical relations for semi-differentiated voltammograms are given; the exponential nature of the theoretical curve is explored; theoretical relations are compared to experimental voltammograms for AgNO₃ in 1 M nitric acid at 298 K, NiCl₂ in LiCl at 974 K, …

Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree

Faculty Publications

One of the grand challenges of amphiphilic self-assembly is the design of ordered structures whose morphology or shape can be explicitly and dynamically controlled by adjusting the properties of the amphiphiles or their surroundings. Such a capacity would enable researchers to create synthetic systems with functionality that meets or exceeds biological cells, and provide a robust platform for a broad range of engineering applications such as artificial tissues, drug delivery, and separation membranes. Despite significant progress, important fundamental questions remain unanswered, due in part to the limited resolution and the restricted parameter spaces that are readily accessible in experiments. Computational …

Control Education For Societal-Scale Challenges: A Community Roadmap, John Anthony Rossiter, Christos G. Cassandras, João Hespanha, Sebastian Dormido, Luis De La Torre, Gireeja Ranade, Antonio Visioli, John Hedengren, Richard M. Murray, Panos Antsaklis, Francoise Lamnabhi-Lagarrigue, Thomas Parisini

Faculty Publications

This article focuses on extending, disseminating and interpreting the findings of an IEEE Control Systems Society working group looking at the role of control theory and engineering in solving some of the many current and future societal challenges. The findings are interpreted in a manner designed to give focus and direction to both future education and research work in the general control theory and engineering arena, interpreted in the broadest sense. The paper is intended to promote discussion in the community and also provide a useful starting point for colleagues wishing to re-imagine the design and delivery of control-related topics …

Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree

Faculty Publications

One of the grand challenges of amphiphilic self-assembly is the design of ordered structures whose morphology or shape can be explicitly and dynamically controlled by adjusting the properties of the amphiphiles or their surroundings. Such a capacity would enable researchers to create synthetic systems with functionality that meets or exceeds biological cells, and provide a robust platform for a broad range of engineering applications such as artificial tissues, drug delivery, and separation membranes. Despite significant progress, important fundamental questions remain unanswered, due in part to the limited resolution and the restricted parameter spaces that are readily accessible in experiments. Computational …

Dynamic Multi-Dimensional Numerical Transport Study Of Lithium-Ion Battery Active Material Microstructures For Automotive Applications, Joseph S. Lopata, Taylor R. Garrick, Fengkun Wang, Han Zhang, Yangbing Zeng, Sirivatch Shimpalee

Faculty Publications

In support of GM’s traction battery efforts, we derived and implemented a method to describe the electrochemical performance of a battery cell considering the nuances of the electrode microstructure at the anode and the cathode and the corresponding impact on the electrochemical transport in the solid and liquid phases. To assess the capability of the method, we compared model results from the microstructure framework with the commonly used continuum-level porous electrode model, commonly referred to as the pseudo-2-dimensional model, or the Newman Model. The microstructure modeling framework was applied to simulate the electrochemical and transport processes within the battery cell …

Sootlib: A Soot Model Library For Combustion Simulation, Victoria B. Stephens, Joshua Bedwell, Alex J. Josephson, Keturah Oldham, David O. Lignell

Faculty Publications

Soot formation in combustion is an important process that affects radiative heat transfer, flame temperatures, and emissions with health and environmental impacts. Soot formation involves complex chemistry for nucleation, growth, oxidation, and coagulation processes. The soot particles vary widely in size and accurate modeling requires representation of the particle size distribution (PSD). Modeling soot is not trivial, and is only one of several physical processes active in combustion systems. This paper presents a software package called SootLib, which is an open-source library for modeling soot formation and other aerosol systems. SootLib is written in C++, is documented with Doxygen, and …

Turbulent Mixing Simulation Using The Hierarchical Parcel-Swapping (Hips) Model, Tommy Starick, Masoomeh Behrang, David O. Lignell, Heiko Schmidt, Alan R. Kerstein

Faculty Publications

Turbulent mixing is an omnipresent phenomenon that permanently affects our everyday life. Mixing processes also
plays an important role in many industrial applications. The full resolution of all relevant flow scales often poses a major challenge to the numerical simulation and requires a modeling of the small-scale effects. In transported Probability Density Function (PDF) methods, the simplified modeling of the molecular mixing is a known weak point. At this place, the Hierarchical Parcel-Swapping (HiPS) model developed by A.R. Kerstein [J. Stat. Phys. 153, 142-161 (2013)] represents a computationally efficient and novel turbulent mixing model. HiPS simulates the effects of turbulence …

Active Control Of Equilibrium, Near-Equilibrium, And Far-From-Equilibrium Colloidal Systems, Mark N. Mcdonald, Qinyu Zhu, Walter F. Paxton, Cameron K. Peterson, Douglas R. Tree

Faculty Publications

The development of top-down active control over bottom-up colloidal assembly processes has the potential to produce materials, surfaces, and objects with applications in a wide range of fields spanning from computing to materials science to biomedical engineering. In this review, we summarize recent progress in the field using a taxonomy based on how active control is used to guide assembly. We find there are three distinct scenarios: (1) navigating kinetic pathways to reach a desirable equilibrium state, (2) the creation of a desirable metastable, kinetically trapped, or kinetically arrested state, and (3) the creation of a desirable far-from-equilibrium state through …

Ash Aerosol Particle Size Distribution, Composition, And Deposition Behavior While Co-Firing Coal And Steam-Exploded Biomass In A 1.5 Mwth Combustor, Rajarshi Roy, Brian Schooff, Xiaolong Li, Scott Montgomery, Jacob Tuttle, Jost O.L. Wendt, Kingsley Dickson, Brian Iverson, Andrew R. Fry

Faculty Publications

Five different blends of Utah bituminous coal and steam-exploded pine (100/0, 75/25, 50/50, 25/75, 0/100 by mass) were fired in a 1.5 MWth combustor. Primary objectives were to understand mineral matter behavior by analyzing aerosol size distribution, aerosol size-segregated composition, ash deposition mass, and ash composition. For particle size < 0.1 μm, pure coal had the lowest aerosol concentration and pure biomass showed the highest (higher nucleation of potassium salts), a trend which reversed for particles >0.1 μm. During pure biomass combustion, aerosol particles >15 μm contained higher mass fractions of potassium (+126%), calcium (+132%), and iron (+115%) and lower fractions of aluminum (−49%) and silicon (−29%) than pure coal. Ash deposition mass decreased with increasing biomass blends. …

Steering Particles Via Micro-Actuation Of Chemical Gradients Using Model Predictive Control, Mark N. Mcdonald, Cameron K. Peterson, Douglas R. Tree

Faculty Publications

Biological systems rely on chemical gradients to direct motion through both chemotaxis and signaling, but synthetic approaches for doing the same are still relatively naïve. Consequently, we present a novel method for using chemical gradients to manipulate the position and velocity of colloidal particles in a microfluidic device. Specifically, we show that a set of spatially localized chemical reactions that are sufficiently controllable can be used to steer colloidal particles via diffusiophoresis along an arbitrary trajectory. To accomplish this, we develop a control method for steering colloidal particles with chemical gradients using nonlinear model predictive control with a model based …