Engineering Commons^™

Household Income And Air Pollution At Public Schools In The United States, Katyland Facas, Kristina Wagstrom

Honors Scholar Theses

Poor air quality at schools may negatively impact students’ academic performance.1 2 3 In this study we look at the relationship between ambient, outdoor air quality and student socioeconomic status at United States public schools. We used free and reduced lunch eligibility, as part of the USDA’s National School Lunch Program, as an indicator of household income. We focus on nitrogen dioxide (NO2), ozone (O3), and particulate matter smaller than 2.5 microns (PM2.5). We used ambient pollutant concentration estimates at census block group resolution (Kim et al.) as the outdoor air pollution concentration at each school.4 We found a positive …

Sequence And Entropy-Based Control Of Complex Coacervates, Li-Wei Chang, Tyler K. Lytle, Mithun Radhakrishna, Joel J. Madinya, Jon Vélez, Charles E. Sing, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Biomacromolecules rely on the precise placement of monomers to encode information for structure, function, and physiology. Efforts to emulate this complexity via the synthetic control of chemical sequence in polymers are finding success; however, there is little understanding of how to translate monomer sequence to physical material properties. Here we establish design rules for implementing this sequence-control in materials known as complex coacervates. These materials are formed by the associative phase separation of oppositely charged polyelectrolytes into polyelectrolyte dense (coacervate) and polyelectrolyte dilute (supernatant) phases. We demonstrate that patterns of charges can profoundly affect the charge–charge associations that drive this …

Mechanism Of Insulin Aggregation: Applied To Alzheimer's Disease, Milos Atz

Honors Scholar Theses

Alzheimer’s disease, a debilitating neurodegenerative illness, is caused by the irreversible aggregation of beta-amyloid proteins in the brain. In Alzheimer’s brains, the protein can become disfigured, causing it to aggregate into long, insoluble fibers that deposit on brain tissue. Studying the aggregation mechanisms of amyloid proteins can lead to a deeper understanding of the progression of Alzheimer’s disease and possibly point towards a potential cure or treatment for the disease. Heat induced aggregation of insulin provides a model system to study the aggregation of amyloidogenic proteins. This study investigates the early stages of heat induced insulin aggregation using dynamic light …

Avoiding Aggregation During Drying And Rehydration Of Nanocellulose, Evelyn Fairman

Honors College

Nanocellulose has attracted attention from academic researchers and industrial corporations worldwide. It is a sustainable raw material with remarkable strength and rheological properties. The industrial production of nanocellulose is an aqueous process; however, many of its valuableproperties are lost upon water removal. Indeed, once dried, nanocellulose irreversibly assembles into a plastic-like material. Currently it can betoo expensive to transport the aqueous suspensions. In order to mitigate high transportation costs, a methodmust be developed to dry and rehydrate nanocellulose whilst maintaining its nano-morphology. The current work demonstrates that the introduction of a cationic surfactant into the aqueous nanocellulose suspensionyields a chemical …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Hollow Fiber Module For Continuous Ethanol Fermentation, Leia M. Dwyer

Honors Scholar Theses

Continuous processes have several advantages over their batch counterparts and are prevalent across the chemical engineering industry today. The process of brewing beer, however, remains a batch process. Transforming the brewing process into a continuous process could have many advantages including lowered process down-time, increased profits, and higher product homogeneity. This project looked into several aspects of the brewing process to gain insight into the potential for continuous ethanol fermentation. First, a kinetic model was developed for the enzymatic breakdown of starch to simple sugars in the production of wort from malted barley. Next, the growth kinetics of brewer’s yeast, …

Design Focused Computer Module For Chemical Engineering Outreach, Marc Beauchemin

Honors College

The purpose of this project is to propose the use of a computer simulation to provide middle and high school students with a chemical engineering design experience. Long standing collective efforts between the University of Maine Department of Chemical and Biological Engineering and the Pulp and Paper Foundation have resulted in a variety of outreach programs aimed at students of this age. Recently, both organizations have been increasing efforts in these areas, proposing a senior design project focused on making a portable model demonstrating chemical engineering concepts. This project was examined along with other outreach efforts and teaching modules. The …

Slides: Geospatial Decision Support For Shale Gas Site Development, Malcolm Williamson, Jackson Cothren, Peter Smith

Opportunities and Obstacles to Reducing the Environmental Footprint of Natural Gas Development in Uintah Basin (October 14)

Presenter: Malcolm Williamson, Center for Advanced Spatial Technologies, University of Arkansas

50 slides

Effects Of Preparative Parameters On The Structure And Performance Of Ca-La Metal Oxide Catalysts For Oil Transesterification, Shuli Yan, Manhoe Kim, Siddharth Mohan, Steven O. Salley, K.Y. Simon Ng

National Biofuels Energy Laboratory

The effects of preparative parameters on the surface basicity, composition, and transesterification activities of several Ca-La metal oxide catalysts were investigated. Four different preparation methods: ammonia-ethanol-carbon dioxide precipitation, physical mixing, impregnation, and co-precipitation, were studied. It was found that the ammonia-ethanol-carbon dioxide precipitation method resulted in the highest BET specific surface area, base strength and base site concentration. Moreover, catalyst surface composition and basicity are a function of calcination temperature, precipitants, pH, and molar ratio of Ca to La in precursor solution, and storage conditions. XRD, XPS, basicity and BET tests revealed that catalyst structure and dispersion of Ca species …

Patterned Well-Ordered Mesoporous Silica Films For Device Fabrication, Todd A. Crosby

Masters Theses 1911 - February 2014

Developing effective methods of generating thin metal oxide films are important for sensing and separations applications. An obstacle to device fabrication is controlling the size and spatial orientation of domain level pores while retaining the ability to generate arbitrary device level patterns. Well-ordered hexagonally packed cylindrical pores were created by taking advantage of block copolymer self-assembly followed by selective condensation of silica precursors using supercritical carbon dioxide as the solvent. It was possible to control the pore size by choosing PEO-PPO-PEO (Pluronic® series) triblock copolymers of differing molecular weights.

These processes were then incorporated with conventional lithographic techniques to generate …

Synthesis And Adsorption Studies Of The Micro-Mesoporous Material Sba-15, Eunyoung You

Masters Theses 1911 - February 2014

Over the past decades, there have been worldwide efforts to synthesize new types of ordered porous materials for catalysis, separations, etc. Among those, mesoporous material with microporous walls are promising in a sense that while mesopores act as channels for the reactant transport with little diffusion limitation, micropores in the wall act as active sites for reactions or storage of the molecules. In this study, we focused on the SBA-15 material, which is a highly ordered mesoporous silica material with micropores present in the wall. We have studied the synthesis of the material by manipulating various factors that are known …

The Effect Of Oxygen On Nonthermal-Plasma Reactions Of Nitrogen Oxides In Nitrogen, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz

Faculty Publications

NO is mainly converted to NO2 by chemical oxidation in the presence of oxygen. Initial selectivity analysis shows that three electron collision reactions are important for NOX evolution in O2/N2. The rate constants of these reactions decrease with increasing oxygen concentration. This is because oxygen is electronegative and hence reduces the electron concentration. The rate constant of O2 dissociation by electron collision reaction is almost two orders of magnitude higher than that of N2 dissociation. NO formation occurs predominantly through N(2D) + O2 → NO + O. The critical oxygen concentration, defined as the concentration above which the NOX formation …

Potential-Selective Deposition Of Copper From Chloride Solutions Containing Iron, Ralph E. White, James A. Trainham, John Newman, Thomas W. Chapman

Faculty Publications

The hydrometallurgy of copper may involve leaching of the metal from its ore with an aqueous solution containing cupric and ferric chloride. The subsequent deposition of copper from such a process stream is modeled here in an idealized electrochemical cell with a rotating-disk electrode. The potential distribution and concentration profiles within the diffusion layer are predicted for given potential differences between the electrode and the solution. The cuprous ion, which is formed by the reduction of the complexed cupric ion at the electrode, is stabilized in the chloride solution and can react either at the electrode or with ferric species …