Chemical Engineering Commons^™

Conference Program (Gpe 2016), Jamal Chaouki, Franco Berruti, Xiaotao (Tony) Bi, Ray Cocco

Fluidization XV

No abstract provided.

Methodological Considerations Of Electron Spin Resonance Spin Trapping Techniques For Measuring Reactive Oxygen Species Generated From Metal Oxide Nanomaterials, Min Sook Jeong, Kyeong-Nam Yu, Hyun Hoon Chung, Soo Jin Park, Ah Young Lee, Mi Ryoung Song, Myung-Haing Cho, Jun Sung Kim

Chemical & Biomedical Engineering Faculty Publications

Qualitative and quantitative analyses of reactive oxygen species (ROS) generated on the surfaces of nanomaterials are important for understanding their toxicity and toxic mechanisms, which are in turn beneficial for manufacturing more biocompatible nanomaterials in many industrial fields. Electron spin resonance (ESR) is a useful tool for detecting ROS formation. However, using this technique without first considering the physicochemical properties of nanomaterials and proper conditions of the spin trapping agent (such as incubation time) may lead to misinterpretation of the resulting data. In this report, we suggest methodological considerations for ESR as pertains to magnetism, sample preparation and proper incubation …

Light-Activated Photocurrent Degradation And Self-Healing In Perovskite Solar Cells, Wanyi Nie, Jean-Christophe Blancon, Amanda J. Neukirch, Kannatassen Appavoo, Hsinhan Tsai, Manish Chhowalla, Muhammad A. Alam, Matthew Y. Sfeir, Claudine Katan, Jacky Even, Sergei Tretiak, Jared J. Crochet, Gautam Gupta, Aditya D. Mohite

Publications and Research

Solution-processed organometallic perovskite solar cells have emerged as one of the most promising thin-film photovoltaic technology. However, a key challenge is their lack of stability over prolonged solar irradiation. Few studies have investigated the effect of light soaking on hybrid perovskites and have attributed the degradation in the optoelectronic properties to photochemical or field-assisted ion migration. Here we show that the slow photocurrent degradation in thin-film photovoltaic devices is due to the formation of light-activated meta-stable deep-level trap states. However, the devices can self-heal completely by resting them in the dark for <1 min or the degradation can be completely prevented by operating the devices at 0°C. We investigate several physical mechanisms to explain the microscopic origin for the formation of these trap states, among which the creation of small polaronic states involving localized cooperative lattice strain and molecular orientations emerges as a credible microscopic mechanism requiring further detailed studies.

Hydrodynamics And Mass Transfer In Bubble Columns, Onkar N. Manjrekar

McKelvey School of Engineering Graduate Student Theses & Dissertations

Bubble columns and slurry bubble columns are multiphase reactors used for a wide range of applications in the biochemical, chemical, petrochemical, and metallurgical industries. In spite of their widespread usage, the scale-up of bubble columns remains an ongoing challenge. Various scale-up approaches, based on concepts ranging from ideal mixing to complex 3-D multiphase CFD models, have been used for assessing the effect of column size and gas and liquid flow rates on column hydrodynamics and reactor performance. Among these approaches, phenomenological models based on either single-class or multi-class bubbles that were validated on cold flow systems have been successful in …

Optical Probes In Multiphase Reactors, Boung Wook Lee

McKelvey School of Engineering Graduate Student Theses & Dissertations

This dissertation examines the application of optical probe techniques in two predominant multiphase reactors used for contacting gas and liquid phases: bubble column reactors and gas-liquid stirred tank reactors. Multiphase reactors are ubiquitous in industry, and for most processes, successful operation depends on successful inter- and intra-phase contacting and mixing. Extensive modeling and experimental research efforts have been made for better reactor design, modeling, and scale-up, yet, much remains unknown about the gas phase.

Optical probes offer significant advantages for gas phase dynamics measurements. Consequently, they have been adapted by numerous researchers around the world for detailed fluid dynamic investigations …

Development Of Steady-State And Dynamic Flux Models For Broad-Scope Microbial Metabolism Analysis, Lian He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Flux analysis techniques, including flux balance analysis (FBA) and 13C-metabolic flux analysis (MFA), can characterize carbon and energy flows through a cells metabolic network. By employing both 13C-labeling experiments and nonlinear programming, 13C-MFA provides a rigorous way of examining cell flux distributions in the central metabolism. FBA, on the other hand, gives a holistic review of optimal fluxomes on the genome scale. In this dissertation, flux analysis techniques were constructed to investigate the microbial metabolisms.

First, an open-source and programming-free platform of 13C-MFA (WUFlux) with a user-friendly interface in MATLAB was developed, which allowed both mass isotopomer distribution (MID) analysis …

Modeling, Simulation, And Analysis Of Lithium-Ion Batteries For Grid-Scale Applications, Matthew Thomas Lawder

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lithium-ion batteries have become universally present in daily life, being used across a wide range of portable consumer electronics. These batteries are advantageous compared to other forms of energy storage due to their high energy density and long cycle life. These characteristics make lithium-ion batteries advantageous for many new and developing applications that require large scale energy storage such as electric vehicles and the utility grid. Typical uses for lithium-ion batteries require consistent cycling patterns that are predictable and easy to approximate across all uses, but new large scale applications will have much more dynamic demands. The cycling patterns for …

Highly Conductive In-Sno2/Rgo Nano-Heterostructures With Improved Lithium-Ion Battery Performance, Ying Liu, Alessandro Palmieri, Junkai He, Yongtao Meng, Nicole Beauregard, Steven L. Suib, William E. Mustain

Faculty Publications

The increasing demand of emerging technologies for high energy density electrochemical storage has led many researchers to look for alternative anode materials to graphite. The most promising conversion and alloying materials do not yet possess acceptable cycle life or rate capability. In this work, we use tin oxide, SnO2, as a representative anode material to explore the influence of graphene incorporation and In-doping to increase the electronic conductivity and concomitantly improve capacity retention and cycle life. It was found that the incorporation of In into SnO2 reduces the charge transfer resistance during cycling, prolonging life. It is also hypothesized that …

Microstructure And Rheology Of Carbon Nanotubes At Air-Water Interfaces, Charles D. Young

Honors Scholar Theses

This work characterizes the material properties of carbon nanotubes at air-water interfaces for potential use in creating stable emulsions. Properties such as length, aspect ratio, contact angle, microstructural ordering, surface pressure, compression and shear elastic moduli, stresses, surface viscosities and non-linearity are explored. Challenges such as deviation from a classical analysis of monolayers are encountered in the form of aggregation, mechanical contributions, and interface relaxation. These factors are taken into account to explain experimental measurements and trends. Ultimately, existing models for more homogeneous systems are resolved with observations to offer insight and areas of promise moving forward.

Hybrid Sulfur Process For Solar Production Of Hydrogen, John Jacob Isenhower, Katherine Cross Henderson, Nicholas Joseph Eigenbrot

Senior Theses

Lowering dependence on fossil-based fuels has become a major area of focus in research, especially in transportation fuels. One particularly interesting field is that of hydrogen production. Hydrogen is promising because it has the potential to emit no greenhouse gases when used as fuel and is an excellent vessel for energy storage. Because traditional methods for its generation are inefficient and require nonrenewable fuel use, researchers have begun to focus on thermochemical cycles.

Thermochemical cycles are systems that require heat transfer intrinsically and do not consume fossil fuels nor emit greenhouse gases if renewable energy is used for heating. The …

Thermal Stability And Crystallinity In Sputtered Scandia Stabilized Zirconia Thing Films, Patrick Mackenzie Barboun

Senior Theses

This senior thesis project studies the synthesis of solid oxide fuel cell electrolytes using magnetron sputtering. Materials used in bilayer electrolytes were studied individually for phase stability.

Order Reduction Of Dae Models, John Hedengren, Thomas F. Edgar

Faculty Publications

This report outlines a technique for the order reduction of differential algebraic equations (DAEs). The order reduction is accomplished in two steps. First, algebraic states are partitioned into successive implicit sets of variables and equations by reconstructing the sparsity pattern into lower triangular block form. Second, proper orthogonal decomposition (POD) is used to reduce the number of differential states. As a test case for the theory, a dynamic binary distillation column model is analyzed with the generalized approach. The index 1 DAE model of 52 differential and 178 algebraic states is reduced to an ODE model of 26 differential states.

Asset Management Model For An Industrial Process Automations System In The Chemical Engineering Unit Operations Laboratory At Rose-Hulman Institute Of Technology, Megan Elaine Liebman

Graduate Theses - Chemical Engineering

In the Chemical Engineering curriculum, the Unit Operations (UO) Laboratory is recognized as the place where hands-on exposure to industrial practices occurs. Students not only examine fundamental engineering principles, but also gain knowledge of the intricacies of modern control technology. The UO Laboratory at Rose-Hulman Institute of Technology houses an industrial state-of-the-art distributed control system, which operates eleven large-scale experiments and interfaces with approximately two hundred process instruments. The size and complexity of the distributed control system and its associated equipment have grown over the past ten years and have reached a point where a systematic asset management approach is …

Nanofiltration Rejection Of Contaminants Of Emerging Concern From Municipal Water Resource Recovery Facility Secondary Effluents For Potable Reuse Applications, Steven Michael Jones

Graduate Theses and Dissertations

As reuse of municipal water resource recovery facility (WRRF) effluent becomes vital to augment diminishing fresh drinking water resources, concern exists that conventional barriers may prove deficient and the upcycling of contaminants of emerging concern (CECs) could prove harmful to human health and aquatic species if more effective and robust treatment barriers are not in place.

There are no federal Safe Drinking Water Act (SDWA) regulations in place specifically for direct potable reuse (DPR) of WRRF effluent. Out of necessity, some states are developing their own DPR reuse regulations. Currently, reverse osmosis (RO) is the default full advanced treatment (FAT) …

Developing Modeling, Optimization, And Advanced Process Control Frameworks For Improving The Performance Of Transient Energy-Intensive Applications, Seyed Mostafa Safdarnejad

Theses and Dissertations

The increasing trend of world-wide energy consumption emphasizes the importance of ongoing optimization of new and existing technologies. In this dissertation, two energy–intensive systems are simulated and optimized. Advanced estimation, optimization, and control techniques such as a moving horizon estimator and a model predictive controller are developed to enhance the profitability, product quality, and reliability of the systems. An enabling development is presented for the solution of complex dynamic optimization problems. The strategy involves an initialization approach to large–scale system models that both enhance the computational performance as well as the ability of the solver to converge to an optimal …

Haul Truck Tires Recycling, Jessica N. Lizarazu

Chemical Engineering Undergraduate Honors Theses

The disposal of large Off-the-Road (OTR) tires is an increasingly important concern. These tires can weigh up to 8,450 pounds with an overall diameter and width of approximately 140.7 inches and 45.1 inches respectively. OTR tires are used for mining vehicles such as haul trucks, wheel loaders, backhoes, graders, and trenchers. These new tires cost between $38,000 and $50,000 each, depending on multiple factors including oil prices and the cyclical nature of the industry. Haul trucks contain six tires per vehicle, and mines replace these tires around every 9-12 months. Statistics regarding discarded OTR tires are not provided by the …

Removal Of Endocrine Disrupting Compounds From Secondary Municipal Wastewater, Dustin R. Resz

Chemical Engineering Undergraduate Honors Theses

Approximately 1.2 billion people around the world live in areas of physical water scarcity. This could increase to half of the world’s population by 2030 and could displace 24 to 700 million people unless steps are taken to ensure adequate water supply.1 Water scarcity is an escalating issue within the United States, specifically in Western inland states with arid climates. This scarcity is encouraging communities to investigate tertiary level municipal wastewater treatment, allowing for reuse of wastewater. Unfortunately, wastewater contains numerous contaminants that are not regulated by the Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA). Many …

Development Of An Inflammatory Joint Fluid Corrosion Assessment Method For Metallic Biomaterials, Kathleen Pieri

Renée Crown University Honors Thesis Projects - All

There is currently no systematic way to analyze the corrosion response of orthopedic alloys in contact with human joint fluid. The goal of this project was to design and test a small device that can successfully run electrochemical tests on retrieved inflamed joint fluids. Methods of fluid testing analysis were also explored. The a small electrochemical cell was created using polypropylene for the body and an electrode cartridge that could be disposed of after each test. In total the device could hold 4 mL of liquid. Testes were preformed using titanium, stainless steel, and CoCrMo alloys as the working electrodes …

Cloning, Fed-Batch Expression And Purification Of A Novel Anti-Candida Peptide And Development Of A Cleavage Resistant Variant Of Green Fluorescence Protein, Rudra Palash Mukherjee

Graduate Theses and Dissertations

This work illustrates that the intelligent design of a bioprocess for the production of peptides of various length is possible by having a prior knowledge of desired product, cell line, fermentation conditions, and choices for downstream recovery. Cloning, expression, and recovery of a novel 12-mer anti-Candida peptide served as an illustrative case for a proposed Escherichia coli platform. The antifungal peptide, expressed as a fusion to GFPUV during high call density fed-batch, was recovered from cell lysate, concentrated using ion exchange chromatography, and finally cleaved with cyanogen bromide. The platform was capable of producing active peptide capable of arresting the …

Efficiency And Particulate Matter Emissions Testing Of Wood Burning Heating Units, Collin W. Michael

Chemical Engineering Undergraduate Honors Theses

The University of Arkansas StoveHOGS team developed a method for efficiency and particle emissions testing of wood fired heaters. The EPA currently regulates the particulate emissions of wood burning stoves, and the goal of this project was to develop a cheaper, easier method for small manufacturers to test the efficiency and particulate emissions of wood burning stoves without sending them to a testing facility. The team used EPA and CSA testing standards to design and test a method that could accomplish the same task in a simpler and more cost effective manner.