Digital Commons Network^™

Fabrication And Optical Properties Of Noble Metal Nanostructures, Mark Kinnan

All Dissertations

Experimental and theoretical results are presented in Chapters 2, 3, and 4 on the effects of dielectric medium, particle size, and interparticle distance, respectively, on plasmon coupling in two-dimensional arrays of silver nanoparticles. The arrays were fabricated via the self-assembly of single crystal particles from c.a. 46 nm to 287 nm on PVP-modified glass substrates. Spin-coated poly(methylmethacrylate) layers were used to immobilize the particles and prevent their surface aggregation. Varying the thickness of the PMMA layer made it possible to change the average dielectric medium between the particles. UV-Visible spectra of different arrays were compared to the corresponding electron microscope …

Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash

All Dissertations

Piezoelectrically-driven (piezoactive) systems such as nanopositioning platforms, scanning probe microscopes, and nanomechanical cantilever probes are advantageous devices enabling molecular-level imaging, manipulation, and characterization in disciplines ranging from materials science to physics and biology. Such emerging applications require precise modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. This dissertation presents a comprehensive modeling and control framework for piezoactive micro and nano systems utilized in various applications.
The development of a precise memory-based hysteresis model for feedforward tracking as well as a Lyapunov-based robust-adaptive controller for feedback tracking control of nanopositioning stages are …

Calculations Of Diffusion In Fcc Binary Alloys Using On-The-Fly Kinetic Monte Carlo, Erdi Bleda

All Dissertations

With the recent advancements in computer technologies and the improvements in simulation algorithms, along with the theories, has allowed scientists to carry out diffusion calculations more efficiently, especially for the cases where either the diffusion itself takes longer, or there is no available isotope to carry out the diffusion experiments such as tracer diffusion.
In this work, we present a systematic approach to diffusion in intermetallic alloys such as weakly clustered Cu — Ni and weakly ordered Au — Ag. We use Accelerated Molecular Dynamics (AMD) combined with the Embedded Atom Method (EAM) to find the necessary saddlepoint energies. With …

Fluorescent Conjugated Polymer Dots For Single Molecule Imaging And Sensing Applications, Changfeng Wu

All Dissertations

While single molecule imaging and sensing hold the promise of providing unprecedented detail about cellular processes, many advanced applications are limited by the lack of appropriate fluorescence probes. In many cases, currently available fluorescent labels are not sufficiently bright and photostable to overcome the background associated with various autofluorescence and scattering processes. This dissertation describes research efforts focused on the development of a novel class of fluorescent nanoparticles called conjugated polymers dots (CPdots) for single molecule fluorescence detection. The CPdots contain highly fluorescent π-conjugated polymers that have been refined over the last decades as the active material in polymer light-emitting …

Synthesis, Characterization, And Application Of Ag Nanostructures, Stephen Hudson

All Dissertations

Noble metal nanoparticles (NPs) have been used for many centuries; however their properties were not truly scrutinized until Michael Farady's investigations in the 1850's. Advances in the field of nanotechnology over the last three decades have enabled insights into the properties of materials as their dimensions are reduced to the nanoscale. The repercussions of these insights are seen in many modern applications.
In this dissertation, properties of novel nanostructures based on Ag NPs are presented and discussed. The exceptional optical properties of Ag NPs stem from the collective oscillations of the conduction electrons known as plasmon resonances. The excitation of …

Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy

All Dissertations

The composition and behavior of surfaces and interfaces play a pivotal role in dictating the overall efficiency of the majority of polymeric materials and devices. Surface properties of the materials can be altered using surface modification techniques. It is necessary to highlight that successful methods of surface modification should affect only the upper layer of the polymer material without changing bulk properties. The processes must introduce new functionalities to the surface, optimize surface roughness, lubrication, hydrophobicity, hydrophilicity, adhesion, conductivity, and/or biocompatibility.
Research presented in this dissertation is dedicated to the synthesis, characterization, and application of thin macromolecular layers anchored to …

Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane

All Dissertations

Cardiovascular diseases are the leading cause of death worldwide. Blood vessel replacement is a common treatment for vascular diseases such as atherosclerosis, restenosis and aneurysm, with over 300,000 bypass procedures performed each year. However, vein grafts are limited due to their availability. Although synthetic vascular replacements have been successful for large diameter arteries, they have shown minimal success in arteries with diameters <6mm. This is because most synthetic materials induce thrombus formation which, within a few months of implantation, causes failure of the vascular graft due to occlusion. Tissue engineering is a promising approach to the fabrication of non-thrombogenic vascular grafts, but a reliable and expandable cell source for tissue-engineered vascular graft (TEVG) has not been established.
The work presented here is motivated by the current unavailability of an ideal tissue engineered blood vessel replacement. Our overall goal is to create a living tissue engineered vascular graft that is biodegradable, non-thromobogenic, presents low antigenicity and …

Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee

All Dissertations

Attempts to control sediment-containing runoff and associated water quality problems have involved the establishment of many small to medium sediment retention ponds and the injection of nonionic and anionic polyacrylamide (PAM) flocculants to enhance colloid removal. However, to date use has been driven more by practicing engineers and trial-and-error approaches than by logical and consistent design approaches. Therefore, the purpose of this research was to optimize colloidal clay removal in PAM-aided sediment retention ponds by applying experimental and theoretical methodologies.
Initially, simple measurement techniques for the molecular weight (MW) and charge density (CD) of various PAMs were tested and their …

Topographic Analysis And Predictive Modeling Using Geographic Information Systems, Steven Hall

All Dissertations

This dissertation describes three GIS models developed to better model topographic features and the occurrence of mountain laurel (Kalmia latifolia) in the southern Appalachian Mountains. The first study presented 'A LiDAR based GIS model to calculate Terrain Shape Index on a landscape scale', attempts to develop a GIS based model to calculate the Terrain Shape Index (TSI). TSI is typically collected in the field using a series of elevation measurements to determine the average elevation change within the study plot. In this study, a GIS model is developed and TSI values compared to those collected using conventional methods. The second …

Two Categories Of Refutation Decision Procedures For Classical And Intuitionistic Propositional Logic, Edward Doyle

All Dissertations

An automatic theorem prover is a computer program that proves theorems without the assistance of a human being. Theorem proving is an important basic tool in proving theorems in mathematics, establishing the correctness of computer programs, proving the correctness of communication protocols, and verifying integrated circuit designs.
This dissertation introduces two new categories of theorem provers, one for classical propositional logic and another for intuitionistic propositional logic. For each logic a container property and generalized algorithm are introduced.
Many methods have been developed over the years to prove theorems in propositional logic. This dissertation describes and presents example proofs for …

Computional Modeling Of Precision Molding Of Aspheric Glass Optics, Balajee Ananthasayanam

All Dissertations

In this dissertation, research in two parallel directions is presented; the first involves the prediction of the final size and shape of a glass lens during a precision glass lens molding process and the second introduces a method to compute and quantify the importance of higher order terms in fracture mechanics for different modes of fracture.
The process of precision lens molding has received attention in recent years due to its potential to mass produce aspherical lenses. Aspherical lenses have significantly better optical properties and conventional lens making techniques are limited to manufacturing of spherical lenses only. The conventional technique …

Development Of A Low Cost Controller And Navigation System For Unmanned Ground Vehicle, Shashidhar Muppidi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this research was to develop an Unmanned Ground Vehicle (UGV) which is capable of autonomously navigating to user specified Global Positioning System (GPS) waypoints. For rapid design and testing of the UGV, it was initially designed in a distributive approach using independent commercial off-the-shelf (COTS) computing modules for control and sensing. Autonomous navigation behavior of the UGV was tested to analyze the strengths and weaknesses of the UGV design, using digital compass for heading and GPS for location measurements. The UGV waypoint navigation has been observed to be consistent for smooth terrains. Uneven terrains, however, posed a …

Identifying Genomic Signatures For Predicting Breast Cancer Outcomes, Shruti Rathnagiriswaran

Graduate Theses, Dissertations, and Problem Reports (ETD)

Predicting the risk for recurrence in breast cancer patients is a critical task in clinics. Recent developments in DNA microarrays have fostered tremendous advances in molecular diagnosis and prognosis of breast cancer.;The first part of our study was based on a novel approach of considering the level of genomic instability as one of the most powerful predictors of clinical outcome. A systematic technique was presented to explore whether there is a linkage between the degree of genomic instability, gene expression patterns, and clinical outcomes by considering the following hypotheses; first, the degree of genomic instability is reflected by an aneuploidy-specific …

Effects Of Rate Of Feedback And Reinforcement On Novel Responding, Vennessa L. Walker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ten middle-school students were assigned to receive feedback and token reinforcement either every 1 min (HR) or every 15 min (LR). Subjects used a computer program to learn to perform 5 basic algebra skills at high rates and high accuracy. Subjects were yoked with a partner for practice so that each member of the pair completed the same number of items per skill. Subjects were provided with cumulative review worksheets and then were tested for distraction, adduction, and retention. Results suggest that HR facilitates faster acquisition of skills as well as better performance on cumulative reviews, distraction, and retention tests. …

Interactions Between Teachers And Students In Four Co -Taught, Inclusive, Middle School Classrooms, Nancy G. Burton

Graduate Theses, Dissertations, and Problem Reports (ETD)

Co-teaching in inclusive, content classrooms is becoming increasingly more popular as schools work toward the inclusion of significantly more students with special learning needs in the general education environment. Inherent in every classroom environment is the expectation of teacher-student interactions. It is often the relationship between the teacher and the student that provides opportunities for student achievement and success. The daily interactions that occur between teachers and their students set the tone for the successes and failures that may be realized as a result. The purpose of this study, therefore, is to explore and identify both the context and frequency …

Evaluation Of Machine Vision Techniques For Use Within Flight Control Systems, Marco Mammarella

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this thesis, two of the main technical limitations for a massive deployment of Unmanned Aerial Vehicle (UAV) have been considered.;The Aerial Refueling problem is analyzed in the first section. A solution based on the integration of 'conventional' GPS/INS and Machine Vision sensor is proposed with the purpose of measuring the relative distance between a refueling tanker and UAV. In this effort, comparisons between Point Matching (PM) algorithms and Pose Estimation (PE) algorithms have been developed in order to improve the performance of the Machine Vision sensor. A method of integration based on Extended Kalman Filter (EKF) between GPS/INS and …

Synthesis And Characterization Of Biodegradable Polyurethanes For Biomedical Application, Changhong Zhang

All Dissertations

This dissertation constitutes the studies about the biomedical materials research of novel polyurethanes. These elastic and degradable polyurethanes exhibited the potential for drug delivery, scaffold fabrication by novel ink-jet printing technology or other biomedical applications. This dissertation includes two parts about two different types of polyurethanes.
In the first part of this dissertation, we studied a polyurethane that was synthesized from methylene di-p-phenyl-diisocyanate (MDI), polycaprolactone diol (PCL-diol) and N, N-bis (2-hydorxyethyl)-2-aminoethane-sulfonic acid (BES). MDI, PCL-diol and BES were polymerized into polyurethane and served as the hard segment, soft segment and chain extender respectively. The effects of the chain extender BES …

Population Growth And Planned Birth Policy, Yigang Zhang

All Dissertations

China's planned birth policy is based on 'population pessimism', which states population growth affects the income level negatively, though the role of population growth in cross-country growth regressions is ambiguous. There are 'population pessimism', 'population optimism', and 'population neutralism'. Also, a new concept 'demographic dividend' was raised in recent years, which states a rise in the rate of economic growth can be induced because of a rising share of working age people in a population while still holding 'population neutralism'. The planned birth policy results in a decreasing fertility rate, which slows down the population growth and changes the age …

Hybrid Bond-Order Potential For Silicon, Suleiman Oloriegbe

All Dissertations

ABSTRACT
A new hybrid bond-order potential for silicon is developed. The functional form of the potential is derived from hybrid of expressions from empirical bond-order formalism and first principles approximations. The total energy is expressed as the sum of attractive, repulsive and promotion energies. By introducing a screening function derived from approximations to first principles expressions, the potential is made long-ranged by allowing covalent interactions beyond the first nearest neighbor shell of atoms in agreement with quantum mechanical descriptions of the bonding in silicon. Environment-dependent promotion energy is introduced that accurately accounts for energetic interactions due to changes in hybridization …

Development Of An Open Loop Fuzzy Logic Urea Dosage Controller For Use With An Scr Equipped Hdd Engine, Theodore R. Adams

Graduate Theses, Dissertations, and Problem Reports (ETD)

Selective Catalytic Reduction (SCR) has been shown to be the most promising exhaust aftertreatment system for reducing oxides of nitrogen in near term in-use applications. SCRs use the ammonia containing compound urea, as a reducing agent. In order to control the urea dosage during transient operation of the engine, sophisticated control strategies are needed. The goal of this study was to design a controller to achieve the maximum NO x emission reduction possible in the transient mode of engine operation, without causing ammonia slip. The development of an open loop, non-sensor based fuzzy logic urea dosage controller is discussed in …

Program-Assisted Analysis Of The Transverse Pressure Capacity Of Block Stoppings For Mine Ventilation Control, Timothy J. Batchler

Graduate Theses, Dissertations, and Problem Reports (ETD)

Previously a new test procedure, based on rigid arching, had been developed to determine the true transverse pressure capacity of mine ventilation block stoppings. Using this test procedure, a parametric study of the design parameters was tested to determine the arching capability in block stoppings. Theoretical assessments of arching and design equations were developed creating design guidelines based on the physical properties of the block stoppings. Based on these design guidelines, a computer program was developed to simulate the transverse pressure capacity of mine ventilation block stoppings. Inputs from users will generate a set of representative scenarios simulating a particular …

Analysis Of Factors Affecting Wireless Communication Systems In Underground Coal Mines, David P. Mcgraw

Graduate Theses, Dissertations, and Problem Reports (ETD)

Since recent disasters in the mining industry in 2006 the push for a reliable communication system has became a high priority. This thesis will discuss each "wireless" communication system available and/or being developed for underground mines as well as the frequencies that will be used for each system's operation.;The second part of the investigation will be on the factors affecting these frequencies as well as possible ways to model these factors analytically. It is important to understand these factors in order to make intelligent conclusions as to what communication systems will perform adequately in an underground mining environment.;The third area …

Code Comparison Of Methane Hydrate Reservoir Simulators Using Cmg Stars, Manohar Gaddipati

Graduate Theses, Dissertations, and Problem Reports (ETD)

Natural gas is an important energy source contributing to 23% of the total energy consumption in United States. Domestic conventional natural gas production does not keep pace with increase in natural gas demand. Development of new alternatives like natural gas from methane hydrate can play a major role in ensuring adequate future energy supplies in the United States.;Methane hydrates are crystalline solids, very similar to ice, in which non-polar molecules are trapped inside the cages of water molecules. Methane hydrates could be potentially a vast source of energy. It is estimated that the total amount of natural gas trapped inside …

Optimization Of Magnetic Force Microscopy For Retrieval Of Data From An Erased Or Altered Audiotape, Chandar Prasad Palamadai Subramanian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Magnetic force microscopy (MFM) has been used to investigate the potential for retrieving information from an erased or altered audiotape. The audiotape recording process, the reasons for the distortion of signals during the recording process are presented. An in-depth study has been conducted to investigate the effects of MFM operation parameters on the data retrieval process. Most importantly, these include interleave height and tip speed. Interleave height (i.e., the height of the MFM tip above the surface) has been optimized for maximum clarity of MFM images. Tip speed studies have been carried out to optimize the data retrieval time and …

The Professional Development Of Teachers For International Contexts: A Case Study Of Concordia Language Villages' Study Abroad Programs, Michelle L. Thomas

Theses and Dissertations

In the face of globalization, educational institutions the world over have developed institutional learning outcomes that seek to graduate students who are culturally competent. To accomplish this goal, colleges and schools must have a faculty who is prepared to facilitate student growth in this regard or provide the faculty with professional development opportunities to achieve that end.

Concordia Language Villages, an intensive language and culture education program sponsored by Concordia College in Moorhead, Minnesota, is intentional in its mission to prepare young people for responsible citizenship and has professional development opportunities available to personnel in their programs and educators; however, …

A Meta-Analysis Of Adolescent Rampage Shootings And The Potential Interconnectivity To Gifted/Talented Children With Emotional/Behavioral Disorders, Meghan M. Salyers

Theses and Dissertations

On the tenth anniversary of a series of school rampage shootings in Springfield, Oregon, Littleton, Colorado, and Conyers, Georgia, the purpose of this study was to determine whether there were indications of intellectual, academic, or creative giftedness with emotional/behavioral disorders in the perpetrators. In addition, through historiographical methods, this study was designed to allow for themes to surface from the authentic writings of the adolescent shooters.

Similarities in previous research results are reported in the meta-analysis, and categories derived from my analysis of the writings of Kip Kinkel, Eric Harris, Dylan Klebold, and T.J. Solomon are indicated in the analysis …

Making A Connection Between Student Achievement, Teacher Accountability, And Quality Classroom Instruction, Kelli Ballard, Alan Bates

The Qualitative Report

The importance of standardized test results is becoming more prevalent in the structure of classroom instruction and the operation of schools throughout the nation due to pressure on educators and students from various levels of authority. This study looks at the relationship between classroom instruction and standardized test content and the effects this has on students, parents, and teachers. Seventeen fourth grade students, fourteen parents of fourth graders, and fifteen elementary teachers completed surveys. The study describes several positive and negative aspects to standardized tests, along with ideas of who is responsible for test performance. Standardized tests provide comparisons and …

The Private Sector And The Questionable Role Of Social Responsibility In Securing The Nation's Infrastructure, James K. Hayes

Student Scholarship

Society faces many common challenges that the corporate sector can play a large role to help address. Security against terrorism is one such challenge and is an important pre-condition to sustainable development. Moreover, since terrorism often operates outside of the jurisdiction of state authorities, it is becoming clear that governments cannot address this issue alone. In the United States, for example, there is a large portion of the nation's infrastructure that owned by the private sector. Using data obtained from 158 survey responses from security professionals in the public and private sector, our structural equation model determined that while prior …

The Impact Of Emotional Intelligence On Organizational Intelligence: An Applied Study At The General Company For Electrical Industries, Ali H. Altaee, Alaa Dham Hamd

Journal of Economics and Administrative Sciences

The two terms"of fective intelligece and organizational intelligence" is it is the emotional intelligency and organizational intelligency"are considered as one of the contemporany terms which the various organizations started to function them in their activities to in crease their efficiency. This study aims at examining those two terms and the possibility of their functioning them in one of the general organizations and the questionnaire is used as atool to gather information that are distributed on asample consists of (50)employees and selected randomly from various organizationl levels. The most important conclusions: 1-Theneis aweakness in some of affective intelligence dimensions especially in …

An Evaluation Of The "Computer Technology And Programming" Curriculum In The Vocational Higher Education System In Turkey, Oktay C. Adiguzel, Cigdem S. Cardak

Journal of STEM Teacher Education

The purpose of this study was to evaluate the “Computer Technology and Programming” curriculum offered at vocational colleges with a focus on the goals of the curriculum and student thoughts. Document analysis and semi-structured interviews were conducted to gather the data. Results revealed that there were mainly four problematic issues related to the “Computer Technology and Programming” curriculum. These were: poor quality of education, inadequacy of industry-based education, limited areas of specialization, and poor environment and inadequate opportunities. Results were discussed extensively and recommendations were offered regarding the structural problems of vocational colleges and the “Computer Technology and Programming” curriculum.