Digital Commons Network^™

Cure Kinetics, Morphologies, And Mechanical Properties Of Thermoplastic/Mwcnt Modified Multifunctional Glassy Epoxies Prepared Via Continuous Reaction Methods, Xiaole Cheng

Dissertations

The primary goal of this dissertation is to develop a novel continuous reactor method to prepare partially cured epoxy prepolymers for aerospace prepreg applications with the aim of replacing traditional batch reactors. Compared to batch reactors, the continuous reactor is capable of solubilizing and dispersing a broad range of additives including thermoplastic tougheners, stabilizers, nanoparticles and curatives and advancing epoxy molecular weights and viscosities while reducing energy consumption.

In order to prove this concept, polyethersulfone (PES) modified 4, 4’-diaminodiphenylsulfone (44DDS)/tetraglycidyl-4, 4’-diaminodiphenylmethane (TGDDM) epoxy prepolymers were firstly prepared using both continuous reactor and batch reactor methods. Kinetic studies confirmed the chain …

Utilization Of Aqueous Raft Prepared Copolymers To Improve Anticancer Drug Efficacy, Andrew Christopher Holley

Dissertations

The advent of controlled radical polymerization (CRP) techniques, along with advancements in facile conjugation chemistry, now allow synthetic tailoring of precise, polymeric architectures necessary for drug/gene delivery. Reversible addition- fragmentation chain transfer (RAFT) polymerization and its aqueous counterpart (aRAFT) afford quantitative control over key synthetic parameters including block length, microstructure, and placement of structo-pendent and structo-terminal functionality for conjugation of active agents and targeting moieties. The relevance of water-soluble and amphiphilic (co)polymers synthesized by RAFT for in vitro delivery of therapeutics in biological fluids is an especially attractive feature. In many cases, polymerization, binding, conjugation, …

Development Of Workforce Skills: Student Perceptions Of Mentoring In First Robotics, Katie Joan Veal Wallace

Dissertations

In today’s global economy, new workforce competencies are needed for success at both individual and societal levels. The new workforce skills extend beyond basic reading, writing, and arithmetic to include higher order processes such as critical thinking and problem solving. Technical job opportunities have grown by approximately 17%, yet the United States continues to decline in science, technology, engineering and mathematics (STEM) disciplines. Further, U.S. students earn average or below average test scores when compared to other developed countries. Researchers cite the need to incorporate the learning of workplace skills into secondary education curriculum, and advocates call for new teaching …

Modeling That Leads To The Prediction Of Photocatalytic Coatings Characterization, Biju Bajracharya

Dissertations

One of the abundant sources of energy on earth is a solar energy which is the clean and safest energy source. It is also known as universal energy, the most important source of renewable energy available today. On realizing that the light source has a crucial role in daily life, several scientists and researchers from centuries ago have studied to establish photo induced systems and utilized them. Long after the knowledge of thermal energy, photovoltaic energy, and photosynthesis in plants, two prominent scientists, Fujishima and Honda, have discovered the electrochemical photolysis of water with the Titanium dioxide electrode which was …

Fundamental Investigations Of Clay/Polymer Nanocomposites And Applications In Co-Extruded Microlayered Systems, Jeremy John Decker

Dissertations

The second and fourth generations of hydroxylated dendritic polyesters (HBP2, HBP4) were combined with unmodified sodium montmorillonite clay (Na+MMT) in water to generate a broad range of polymer clay nanocomposites from 0 to 100% wt/wt Na+MMT. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to investigate intercalation states of the clay galleries. It was shown that interlayer spacings were independent of generation number and changed over the composition range from 0.5 nm to 3.5 nm in 0.5 nm increments that corresponded to a flattened HBP conformation within the clay tactoids.

The HBP4/Na+MMT systems were investigated to study the …

Development And Applications Of The Expanded Equivalent Fluid Method, Bharath Kumar Kandula

Dissertations

Ocean acoustics is the study of sound in the oceans. Electromagnetic waves attenuate rapidly in the water medium. Sound is the best means to transmit information underwater. Computational numerical simulations play an important role in ocean acoustics. Simulations of acoustic propagation in the oceans are challenging due to the complexities involved in the ocean environment. Different methods have been developed to simulate underwater sound propagation. The Parabolic-Equation (PE) method is the best choice in several ocean acoustic problems. In shallow water acoustic experiments, sound loses some of its energy when it interacts with the bottom. An equivalent fluid technique was …

Improved Efficiency Organic Photovoltaic Cells Through Morphology Control And Process Modification, Qi Wu

Dissertations

Organic photovoltaic (OPV) cells have drawn great attention due to the potential to produce flexible, light weight, affordable solar cells using polymer organic photovoltaic materials; however, the current power conversion efficiency achieved for these systems is too low for widespread implementation of the technology. Morphology and phase separation are key factors determining the performance of organic photovoltaic cells. Precise control of the size and distribution of the phase-separated photoactive domains is necessary for optimum photon-electron conversion. Polyhedral oligomeric silsesquioxane (POSS) nanostructered chemicals have the potential to provide enhanced control of morphology, crystallinity, and phase dispersion in polymeric blend systems. In …

Fluorine Containing Uv-Curable Materials For Advanced Transport Applications, James Thomas Goetz

Dissertations

The characterization of structure, thermal, gas transport, and free volume properties of two unique UV cured polymeric systems are studied and reported. In the initial pursuit of waterproof high water vapor transport membranes, it became apparent that the UV curing of fluorinated materials yielded routes to develop unique materials that fundamentally challenge conventional models for free volume and light gas transport behavior. UV-curing provides a means to rapidly “lock-in” morphologies that are accessible in the small molecule, monomer phase but rapidly become kinetically inaccessible when constraints such as covalent bonding and cross linking limit motion in the polymer system. This …

Reducing Ambiguities In Customer Requirements Through Historical Rule-Based Knowledge In A Small Organization, Silvia Brum Preston

Dissertations

During the elicitation process the requirements for a software application are obtained from the customer. Customers often do not know how to clearly express the requirements of the application to be built, causing requirements to be ambiguous. Many studies have been found to cover different characteristics of the requirements elicitation process including methods for reducing ambiguities in requirements. The methods and findings of these studies were found to be too general when it comes to the specific domain of the requirements and knowledge about the requirements. In addition, some studies did not take into consideration the level of expertise of …

Outlining The Biocidal Mechanisms Of Synthetic Antimicrobial Peptide Mimics, Tyler D. Brown

Honors Theses

Each day, antibiotic resistance affects the livelihood of individuals worldwide, especially in relation to hospital-acquired diseases. In an effort to combat this resistance, antimicrobial peptides, small biopolymers produced naturally by multicellular organisms, can be used to selectively eliminate bacteria and have demonstrated great potential as alternatives to conventional antibiotics. Many naturally-occurring antimicrobial peptides possess high concentrations of lysine and arginine amino acid residues, which are protonated and positively-charged at physiological pH. Herein, we describe the design and synthesis of antimicrobial peptide mimics, using amino acid mimics. N-3-aminopropyl methacrylamide (APMA) and 3-guanidinopropyl methacrylamide (GPMA) monomers mimic the amino acid residues lysine …

Study Of The Structure-Property Relationships That Determine The Effects Of Latexes And Starch Containing Latex Emulsions On The Performance Of The Barrier Coatings (Sub-Coat) For Paper, Joanna Marie Monfils

Master's Theses

The history of carbonless paper dates back to the 1940s. Before this, a carbon copy sheet was needed between sheets of paper to be able to produce one or more copies simultaneously during writing. The pressure from a pen or typewriter would help deposit the ink of the carbon paper onto the blank sheet of paper under the original written sheet to create a “carbon copy.” This method did however, have its disadvantages. Not only did it produce a limited number of copies, but it was also a messy process. So came the creative process of using microencapsulated dyes to …

Synergy Of The Developed 6d Bim Framework And Conception Of The Nd Bim Framework And Nd Bim Process Ontology, Shawn Edward O'Keeffe

Dissertations

The author developed a unified nD framework and process ontology for Building Information Modeling (BIM). The research includes a framework developed for 6D BIM, nD BIM, and nD ontology that defines the domain and sub-domain constructs for future nD BIM dimensions. The nD ontology defines the relationships of kinds within any new proposed dimensional domain for BIM. The developed nD BIM framework and ontology takes into account the current 2D-5D BIM dimensions. There is a synergy between the 6D and nD framework that allows the nD framework and ontology to be utilized as a unified template for future dimensional development. …

New Fault Tolerant Multicast Routing Techniques To Enhance Distributed-Memory Systems Performance, Masoud Esmail Masoud Shaheen

Dissertations

Distributed-memory systems are a key to achieve high performance computing and the most favorable architectures used in advanced research problems. Mesh connected multicomputer are one of the most popular architectures that have been implemented in many distributed-memory systems. These systems must support communication operations efficiently to achieve good performance. The wormhole switching technique has been widely used in design of distributed-memory systems in which the packet is divided into small flits. Also, the multicast communication has been widely used in distributed-memory systems which is one source node sends the same message to several destination nodes. Fault tolerance refers to the …

Preparation And Detection Of Degradation And Chain Scission Events In Epoxy-Amine Networks Using A Profluorescent Nitroxide Probe, Kylee F. Fazende

Honors Theses

Thermosetting polymers comprise a significant part of polymer research that is in progress today because thermosets are especially critical in the field of aerospace composites. In this context the proposed research project is designed to develop a novel method to detect and quantify chain scission and thermal degradation of matrix materials using profluorescent nitroxide probes as well as, to study the interaction of the thermoset with its environment during utilization and property degradation. Acquisition of this knowledge will allow for a better understanding of early, i.e., premacroscopic, thermoset degradation and to establish whether these early events are predictive of material …

Studies On Controlling The Morphology Of An Organic Bulk-Heterojunction Photovoltaic Device To Improve Its Efficiency, Kelly R. Mcleod

Honors Theses

A systematic study of the effects of alteration of processing parameters in combination with incorporation of polyhedral oligomeric silsesquioxane (POSS) molecules on the properties and structure of bulk heterojunction organic photovoltaic cells made from P3HT:PCBM blends was undertaken. On implementing the correct processing protocol, incorporation of POSS molecules with specific structures resulted in considerable enhancement in cell efficiencies. Octaaminophenyl POSS incorporation resulted in a 20% increase in cell efficiency over the control and caused the formation of crystalline, fiber-like structures in the active layer of the photovoltaic cell.

Investigation Of Adhesion And Network Properties In Thiol-Ene Polymer Networks Modified With Catechol Functionality For Improved Stone Conservation, Ethan F.T. Hoff

Honors Theses

In this thesis, thiol-ene networks of pentaerythritol allyl ether (APE) and pentaerythritol tris(3-mercaptopropionate) (PETMP) modified with dopamine acrylamide (DAm) containing catechol functionality were formulated and tested in order to investigate the effect the catechol group has on major network properties and adhesion. DAm-APE-PETMP networks were successfully synthesized and applied to a wide variety of substrates (Glass, Steel, Aluminum, etc.) in order to test adhesion. The networks were also characterized using infrared spectroscopy, photo-dynamic scanning calorimetry, dynamic mechanical analysis, and tensile testing. Improved macroscopic adhesion values over the neat APE-PETMP networks were achieved on a variety of substrates including steel, aluminum, …

Popularity Of Virtual Reality Immersion In Theme Park Attractions Of North America, Jessica A. Jelinski

Honors Theses

Theme parks continually change to incorporate new technology. Since the development of virtual reality, designers of theme park attractions have utilized several different immersion technology systems. Most of the current attractions are based on the Head-Mounted Display system and the Cave Automatic Virtual Environment system. To date, few studies or papers have been published concerning the effect virtual reality and the accompanying immersion technology may have on theme park attractions. One hundred and seventy-eight attractions from eight theme parks were categorized based on level of immersion and then analyzed for this study. Wait times for these attractions were used to …

Error Estimation Techniques To Refine Overlapping Aerial Image Mosaic Processes Via Detected Parameters, William Glenn Bond

Dissertations

In this paper, I propose to demonstrate a means of error estimation preprocessing in the assembly of overlapping aerial image mosaics. The mosaic program automatically assembles several hundred aerial images from a data set by aligning them, via image registration using a pattern search method, onto a GIS grid.

The method presented first locates the images from a data set that it predicts will not align well via the mosaic process, then it uses a correlation function, optimized by a modified Hooke and Jeeves algorithm, to provide a more optimal transformation function input to the mosaic program. Using this improved …

Bemdec: An Adaptive And Robust Methodology For Digital Image Feature Extraction, Isaac Kueth Gang

Dissertations

The intriguing study of feature extraction, and edge detection in particular, has, as a result of the increased use of imagery, drawn even more attention not just from the field of computer science but also from a variety of scientific fields. However, various challenges surrounding the formulation of feature extraction operator, particularly of edges, which is capable of satisfying the necessary properties of low probability of error (i.e., failure of marking true edges), accuracy, and consistent response to a single edge, continue to persist. Moreover, it should be pointed out that most of the work in the area of feature …

Entropy And Certainty In Lossless Data Compression, James Jay Jacobs

Dissertations

Data compression is the art of using encoding techniques to represent data symbols using less storage space compared to the original data representation. The encoding process builds a relationship between the entropy of the data and the certainty of the system. The theoretical limits of this relationship are defined by the theory of entropy in information that was proposed by Claude Shannon. Lossless data compression is uniquely tied to entropy theory as the data and the system have a static definition. The static nature of the two requires a mechanism to reduce the entropy without the ability to alter either …

Inferring Gene Regulatory Networks From Time Series Microarray Data, Peng Li

Dissertations

The innovations and improvements in high-throughput genomic technologies, such as DNA microarray, make it possible for biologists to simultaneously measure dependencies and regulations among genes on a genome-wide scale and provide us genetic information. An important objective of the functional genomics is to understand the controlling mechanism of the expression of these genes and encode the knowledge into gene regulatory network (GRN). To achieve this, computational and statistical algorithms are especially needed.

Inference of GRN is a very challenging task for computational biologists because the degree of freedom of the parameters is redundant. Various computational approaches have been proposed for …