Other Chemical Engineering Commons^™

Probing Cell Membrane And Biofilm Extracellular Matrix Interactions With Tumor Necrosis Factor-Alpha And Interleukin-6 Through Molecular Dynamics Simulations Using A Detailed Chemical Description, Stephen Desalvo

Renée Crown University Honors Thesis Projects - All

Bacterial biofilms are a major cause of persistent infections and diseases with known antibiotic and host immune defense resistances. The interaction of signaling factors, namely small cytokines, with the biofilm and host cell is considered vital to the survival of bacterial biofilms. In this study, molecular dynamics (MD) simulations are performed using coarse-grained biomolecular systems to provide significant insight into medical therapeutic advancements in treating persistent and chronic infections. Specifically, MD simulations of the interaction between signaling factors tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) with a model biofilm matrix with detailed description were performed. Additional simulations were used to …

In-Package Nonthermal Plasma Degradation Of Pesticides On Fresh Produce, N. Misra, Shashi Pankaj, Tony Walsh, Finbarr O'Regan, Paula Bourke, Patrick J. Cullen

Articles

In-package nonthermal plasma (NTP) technology is a novel technology for the decontamination of foods and biological materials. This study presents the first report on the potential of the technology for the degradation of pesticide residues. A cocktail of pesticides, namely Azoxystrobin, Cyprodinil, Fludioxonil and Pyriproxyfen was tested on strawberries. The concentrations of these pesticides were monitored in priori and post- plasma treatment using GC-MS/MS. An applied voltage and time dependent degradation of the pesticides was observed for treatment voltages of 60, 70 and 80 kV and treatment durations ranging from 1 to 5 min, followed by 24 h in-pack storage. …

Combining Monte Carlo Transport And Level Set Surface Evolution For Modeling Vapor Phase Deposition Of Thin Films Over Sub-Micron Features, John Lewis Smith

Graduate Theses - Chemical Engineering

A hybrid scheme is used to model the vapor phase deposition of thin films at the feature scale. The transport of the chemical species to the substrate surface is modeled with a Collisionless Direct Simulation Monte Carlo (DSMC) method. The Level Set Method is used to model the growth of the thin-film on the substrate. The convergence criteria for these methods were not found in literature.

The governing equations for the Level Set Method are, in general, non-linear partial differential equations. The coupling of the DSMC Method with the Level Set Method results in a set of non-Gaussian stochastic non-linear …

Multiscale Modeling Study Of Methanol Oxidation By Ion-Modified Mdh Enzymes, Purnima Kharidehal

Doctoral Dissertations

Enzymes have been considered as molecular electrocatalysts due to their extraordinary characteristics such as their ability to accelerate reactions enormously, to operate under physiological conditions, and to produce fewer by-products during a catalytic reaction. However, enzyme based fuel cells have been reported to have power output and stability limitations, which are restricting the use of this kind of fuel cell to small electronic devices. Methanol dehydrogenase (MDH) is one such enzyme, which oxidizes methanol and other primary alcohols to their corresponding aldehydes. The active site of MDH contains a divalent cation (Ca2+), a co-factor pyrrolo-quinoline quinone (PQQ), several amino acids, …

Continuous Ultra-Thin Mos2 Films Grown By Low-Temperature Physical Vapor Deposition, Christopher Muratore, Jianjun Hu, Baoming Wang, M. Amanul Haque, John E. Bultman, Michael L. Jespersen, Michael E. Mcconney, R. D. Naguy

Chemical and Materials Engineering Faculty Publications

Uniform growth of pristine two dimensional (2D) materials over large areas at lower temperatures without sacrifice of their unique physical properties is a critical pre-requisite for seamless integration of next-generation van der Waals heterostructures into functional devices. This Letter describes a vapor phasegrowth technique for precisely controlled synthesis of continuous, uniform molecular layers of MoS2 on silicon dioxide and highly oriented pyrolitic graphite substrates of over several square centimeters at 350 °C. Synthesis of few-layer MoS2 in this ultra-high vacuum physical vapor deposition process yieldsmaterials with key optical and electronic properties identical to exfoliated layers. The films are composed of …

Optical Properties Of Carbon Microcoils, Muneaki Hikita, Li Cao, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

Carbon microcoils (CMCs) have emerged as versatile material artifacts for a variety of applications due to their helical and spiral structures. Embedded in matrix, CMCs have already been demonstrated for their potential tactile/proximity sensor application. In this study, CMCs were prepared using a conventional chemical vapor deposition method, and then were functionalized with octadecylamine.

Upon photoexcitation, the functionalized CMCs exhibited photoluminescence in the visible region, which has never been found before. Similar to carbon based nanoparticles, the photoluminescence of CMCs was attributed to electron-hole radiative recombination after surface passivation. The results suggested that this kind of fluorescent functionalized CMCs might …

Domain Engineering Of Physical Vapor Deposited Two-Dimensional Materials, Tarek Alam, Baoming Wang, Raghu Pulavarthy, M. Amanul Haque, Christopher Muratore, Nicholas R. Glavin, Ajit K. Roy, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Physical vapor deposited two-dimensional (2D) materials span larger areas compared to exfoliated flakes, but suffer from very small grain or domain sizes. In this letter, we fabricate freestanding molybdenum disulfide (MoS2) and amorphous boron nitride (BN) specimens to expose both surfaces. We performed in situ heating in a transmission electron microscope to observe the domain restructuring in real time. The freestanding MoS2 specimens showed up to 100× increase in domain size, while the amorphous BN transformed in to polycrystalline hexagonal BN (h-BN) at temperatures around 600 °C much lower than the 850–1000 °C range cited in the literature.

Less Is More: Long-Term In Vitro Exposure To Low Levels Of Silver Nanoparticles Provides New Insights For Nanomaterial Evaluation, Kristen K. Comfort, Laura K. Braydich-Stolle, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios.

In this study, we developed and implemented a chronic in vitromodel coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated …

Development Of Cementitious Materials For Adhesion Type Applications Comprising Calcium Sulfoaluminate (Csa) Cement And Latex Polymer, Joshua V. Brien

Theses and Dissertations--Civil Engineering

The objective of this research was to develop high performing polymer modified calcium sulfoaluminate (CSA) cement materials for use in applications requiring superior adhesion characteristics. Little information is available describing interactions of CSA cement containing minor phase tri-calcium aluminate (C₃A) with commonly used admixtures. Given the scarcity of information, a basic approach for developing cementitious materials was followed. The basic approach consisted of four tasks: cement design, admixture design, polymer design and testing developed materials. The iterative, time consuming process is necessary for understanding the influence of specific constituent components on overall system behavior. Results from the cement …

Atomic Layer Deposition, Paul Kubicza

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Reuse Of The Product Obtained On Grinding Kiln Rollers In The Manufacture Of Ceramic Wall Tiles, Mai H. Roushdy, Shereen K. Amin, Marwa Mohamed, Magdi F. Abadir

Chemical Engineering

The production of ceramic tiles and to a lesser extent flat dinner ware and pottery is increasingly being done by firing in roller kilns. These kilns offer several advantages over conventional tunnel kilns: lower fuel consumption, computer controlled firing curves, low maintenance due to lack of kiln cars, rapid firing cycles of less than one hour and the possibility of shutting down the kiln on short notice.1 One recurrent problem in the operation of such kilns is the periodic need to grind the kiln rollers. These are usually fabricated from high alumina clays and are continuously contaminated by depositions of …

Electrospinning Applications Air Filtration And Superhydrophobic Materials, Negar Ghochaghi, Adetoun Taiwo

Graduate Research Posters

Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers. …

Generation Of Multicomponent Polymer Blend Microparticles Using Droplet Evaporation Technique And Modeling Evaporation Of Binary Droplet Containing Non-Volatile Solute, Venkat N. Rajagopalan

Theses and Dissertations--Chemical and Materials Engineering

Recently, considerable attention has been focused on the generation of nano- and micrometer scale multicomponent polymer particles with specifically tailored mechanical, electrical and optical properties. As only a few polymer-polymer pairs are miscible, the set of multicomponent polymer systems achievable by conventional methods, such as melt blending, is severely limited in property ranges. Therefore, researchers have been evaluating synthesis methods that can arbitrarily blend immiscible solvent pairs, thus expanding the range of properties that are practical. The generation of blended microparticles by evaporating a co-solvent from aerosol droplets containing two dissolved immiscible polymers in solution seems likely to exhibit a …

A Multidisciplinary Techno-Economic Decision Support Tool For Validating Long-Term Economic Viability Of Biorefining Processes, Sumesh Sukumara

Theses and Dissertations--Chemical and Materials Engineering

Increasing demand for energy and transportation fuel has motivated researchers all around the world to explore alternatives for a long-term sustainable source of energy. Biomass is one such renewable resource that can be converted into various marketable products by the process of biorefining. Currently, research is taking strides in developing conversion techniques for producing biofuels from multiple bio-based feedstocks. However, the greatest concern with emerging processes is the long-term viability as a sustainable source of energy. Hence, a framework is required that can incorporate novel and existing processes to validate their economic, environmental and social potential in satisfying present energy …

Thermo-Chemical Conversion Of Coal-Biomass Blends: Kinetics Modeling Of Pyrolysis, Moving Bed Gasification And Stable Carbon Isotope Analysis, Abhijit Bhagavatula

Theses and Dissertations--Chemical and Materials Engineering

The past few years have seen an upsurge in the use of renewable biomass as a source of energy due to growing concerns over greenhouse gas emissions caused by the combustion of fossil fuels and the need for energy independence due to depleting fossil fuel resources. Although coal will continue to be a major source of energy for many years, there is still great interest in replacing part of the coal used in energy generation with renewable biomass. Combustion converts inherent chemical energy of carbonaceous feedstock to only thermal energy. On the other hand, partial oxidation processes like gasification convert …

Physiological Fluid Specific Agglomeration Patterns Diminish Gold Nanorod Photothermal Characteristics, Kristen K. Comfort, Jared W. Speltz, Bradley M. Stacy, Larry R. Dosser, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

Investigations into the use of gold nanorods (Au-NRs) for biological applications are growing exponentially due to their distinctive physicochemical properties, which make them advantageous over other nanomaterials. Au-NRs are particularly renowned for their plasmonic characteristics, which generate a robust photothermal response when stimulated with light at a wavelength matching their surface plasmon resonance. Numerous reports have explored this nanophotonic phenomenon for temperature driven therapies; however, to date there is a significant knowledge gap pertaining to the kinetic heating profile of Au-NRs within a controlled physiological setting. In the present study, the impact of environmental composition on Au-NR behavior and degree …

The Use Of Near Infrared And Microwave Sensing For On-Line Real Time Monitoring Of Moisture Content And Composition Of Powder Blend, Ryan V. Mcdonnell, Anshu Gupta, John Austin, Michael T. Harris, Gintaras V. Reklaitis

The Summer Undergraduate Research Fellowship (SURF) Symposium

Online process analytics has been a topic of interest by pharmaceutical companies as a method of determining how operating parameters affect the final quality of their products. One form of online process analytics that has been found to be effective is microwave sensing. While it has been found that microwave resonance sensing can be used to measure parameters such as moisture content and density, it has yet to be discovered if such sensors have the ability to measure changes in content uniformity of raw materials pharmaceutical companies use. Data was collected using a spin riffler fitted with a microwave sensor …

Tobacco Mosaic Virus Implemented As An Interfacial Layer In Organic Photovoltaic Cells, Monica D. Del Real, Bryan Boudouris

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic photovoltaics (OPVs) are flexible, light weight, and economical to produce due to low processing temperatures, solution processing, and print fabrication. This makes them optimal for a wide range of applications. However, the efficiencies of OPVs are currently not high enough for them to be viable in the market or to be able to compete with inorganic photovoltaics. Therefore the integration of new materials and methods into OPVs in order to increase their efficiency is a vital field. One way to increase the efficiency of OPVs is to increase the surface area in-between layers to allow for enhanced electron transport. …

The Biological Impact Of Concurrent Exposure To Metallic Nanoparticles And A Static Magnetic Field, Kristen K. Comfort, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

The rapid advancement of technology has led to an exponential increase of both nanomaterial and magnetic field utilization in applications spanning a variety of sectors. While extensive work has focused on the impact of these two variables on biological systems independently, the existence of any synergistic effects following concurrent exposure has yet to be investigated. This study sought to ascertain the induced alterations to the stress and proliferation responses of the human adult low calcium, high temperature keratinocyte (HaCaT) cell line by the application of a static magnetic field (approximately 0.5 or 30 mT) in conjunction with either gold or …

Multiscale Modeling Of Enzyme-Catalyzed Methanol Production By Particulate Methane Monooxygenase, Katherine K. Bearden

Doctoral Dissertations

In this work, the conversion of methane to methanol by the particulate Methane Monooxygenase (pMMO) enzyme is investigated using a multi-scale modeling approach. This enzyme participates in carbon cycling and aids in the removal of harmful atmospheric methane, converting it to methanol. The interaction between pMMO and a neighboring enzyme that is present in the same organism is studied, and the unknown pMMO active site is elucidated and tested for methane oxidation towards the production of methanol.

Fundamental knowledge of pMMO's mechanism is not fully understood. Understanding how this enzyme works in nature will provide information towards designing efficient synthetic …