Digital Commons Network^™

Obstruction Sets For Classes Of Cubic Graphs, Joshua Hughes

Doctoral Dissertations

This dissertation establishes two theorems which characterize the set of minimal obstructions for two classes of graphs. A minimal obstruction for a class of graphs is a graph that is not in the class but every graph that it properly contains, under some containment relation, is in the class. In Chapter 2, we provide a characterization of the class of cubic outer-planar graphs in terms of its minimal obstructions which are also called cubic obstructions in this setting. To do this, we first show that all the obstructions containing loops can be obtained from the complete set of loopless obstructions …

Microencapsulation Techniques Towards Building A Sensor: A Study Of Factors Affecting Enzyme Encapsulation And Stability, Suman R. Nayak

Doctoral Dissertations

Minimally and non-invasive glucose sensing techniques are instrumental in improving the quality of life of diabetics, point-of-care testing, critical care monitoring, development of new anti-diabetic drugs or therapeutic compounds, and the study of basic physiology. The overall goal of this project was to build a fluorescent glucose sensor by incorporating relevant sensing chemistry within microcapsules. The specific aims for this research were to study various processes used for the fabrication of micro-containers, the use of these for encapsulation purposes, and the application of the encapsulated system towards glucose sensing. The following is a brief description highlighting the key areas of …

Relationships Among Classroom Technology Utilization, Professional Development, And Knowledge About Technology For Secondary Teachers, Stacy L. King

Doctoral Dissertations

The purpose of this study was to investigate the effects of technology professional development for secondary teachers toward the usage of that technology in the classroom to assist with the teaching/learning process. This research also examined the effects of knowledge about technology for secondary teachers on the utilization of technology in the classroom. Data were gathered from the Technology Proficiency Self Assessment Instrument issued by the Louisiana State Department of Education. The target population consisted of secondary school teachers in Louisiana from 202 secondary schools in twenty-eight parishes. From the 202 secondary schools in Louisiana, a sample of teachers (n …

Biosensing With Microcantilever-Based Sensors, Xiaodong Yan

Doctoral Dissertations

Microcantilevers provide an ideal platform for biosensors. The micron-sized transducer brings several advantages, such as high sensitivity, small sample quantity for analysis, portability, implantable sensor devices, and the ability to be mass produced and integrated into standard microelectronic processing technologies like complementary metal oxide seminconductors (CMOS).

The objective of this research is to investigate and develop modification methods of microcanitlevers for biosensing applications.

Two microcantilever modification methods were investigated. They are self-assembly monolayer method and layer-by-layer method. A fundamental procedure for modification of microcantilevers using the layer-by-layer approach was developed for the first time in this research. These modification methods …

Development Of A Novel Microreactor For Improved Chemical Reaction Conversion, Yu Liang

Doctoral Dissertations

Microreactors have been widely studied over the past two decades for different chemical reactions, to develop new analytical capabilities, and to obtain high mixing performance in the reactors. The main objectives of this work are to investigate the effect of different microchannel structures on the fluid properties and mixing behavior in microreactors, and to design, fabricate, and test a novel microreactor for higher conversion in a chemical reaction. The development of this novel microreactor is intended to provide a valuable guideline in achieving enhanced chemical mixing and to make available a solid research base for optimization of the yield of …

A Numerical Method For Obtaining An Optimal Temperature Distribution In A 3d Triple-Layered Cylindrical Skin Structure, Le Zhang

Doctoral Dissertations

In recent years, it has been interesting to research hyperthermia combined with radiation and cytotoxic drugs to enhance the killing of tumors. The crucial problem is that when heating the tumor tissues, one needs to keep the surrounding normal tissue below a temperature that will produce harm. Thus, it is important to obtain the temperature field of the entire treatment region. The objective of this dissertation is to develop a numerical model for obtaining an optimal temperature distribution in a 3D triple-layered cylindrical skin structure. To this end, we pre-specify the temperatures to be obtained at the center and perimeter …

Intelligent Control Of Nonlinear Systems With Actuator Saturation Using Neural Networks, Wenzhi Gao

Doctoral Dissertations

Common actuator nonlinearities such as saturation, deadzone, backlash, and hysteresis are unavoidable in practical industrial control systems, such as computer numerical control (CNC) machines, xy-positioning tables, robot manipulators, overhead crane mechanisms, and more. When the actuator nonlinearities exist in control systems, they may exhibit relatively large steady-state tracking error or even oscillations, cause the closed-loop system instability, and degrade the overall system performance. Proportional-derivative (PD) controller has observed limit cycles if the actuator nonlinearity is not compensated well. The problems are particularly exacerbated when the required accuracy is high, as in micropositioning devices. Due to the non-analytic nature of the …

The Bipartite Clique: A Topological Paradigm For Web User Search Customization And Web Site Restructuring, Brenda F. Choyce-Miles

Doctoral Dissertations

The objective of this dissertation research is to aid the Web user to achieve his search objective at a host Web site by organizing a strongly connected neighborhood of Web pages that are thematically and spatially related to the user's search interest. Therefore, methods were developed to (1) find all Web pages at a given Web site that are thematically similar to a user's initial choice of a Web page (selected from the set of Web pages returned in response to a query by any popular search engine), and (2) organize these pages hierarchically in terms of their relevance to …

Integrated Modeling And Parallel Computation Of Laser-Induced Axisymmetric Rod Growth, Hong Lan

Doctoral Dissertations

To fully investigate a pyrolytic Laser-induced chemical vapor deposition (LCVD) system for growing an axisymmetric rod, a novel integrated three-dimensional mathematical model was developed not only to describe the heat transport in the deposit and substrate, but also to simulate the gas-phase in the heated reaction zone and its effect on growth rate. The integrated model consists of three components: the substrate, rod, and gas-phase domains. Each component is a separate model and the three components are dynamically integrated into one model for simulating the iterative and complex process of rod deposition.

The gas-phase reaction is modeled by the gas-phase …

Dilation Of The Oropharynx Via Selective Stimulation Of The Hypoglossal Nerve, Jingtao Huang

Doctoral Dissertations

Obstructive sleep apnea (OSA) is caused by the retraction of the tongue to occlude the upper airway (UAW). Electrical stimulation of the tongue protrudor and retractor muscle has been demonstrated as an effective technique to alleviate UAW obstructions and is considered to be a potential treatment for OSA. Recent studies have shown that selective stimulation of the hypoglossal nerve (HG) to activate tongue muscles using a single implantable device presents an attractive approach for treating OSA. In this study, the functional outcome of selective hypoglossal nerve stimulation with a multi-contact peripheral nerve electrode was studied by imaging the airway in …

Innovation And Institutions: Examining The Black Box, Edinaldo Tebaldi

Doctoral Dissertations

This dissertation contributes to the literature by investigating the links between institutions and innovation from both a theoretical and an empirical standpoint. Specifically, this dissertation (i) develops a theoretical growth model that explicitly accounts for the influences of institutions on technical innovation and output production; (ii) specifies an empirical model suitable to examine the affect of institutions on technical innovation based on a theoretical model; and (iii) tests if different measures of institutions (i.e., Control of Corruption, Rule of Law, Regulatory Quality and Expropriation Risk) have differentiated impacts on innovation.

A major prediction of the theoretical model is that better …

Spatial Distribution Of The Common Loon (Gavia Immer) In New Hampshire, Mark W. Brennan

Doctoral Dissertations

The Common Loon (Gavia immer) is located in many portions of North America. By the early 1970's the Common Loon population in New Hampshire had experienced a dramatic decline in historic numbers. In 1975, the Audubon Society of New Hampshire recognized this problem and established the Loon Preservation Committee (LPC). The intent was to collect information regarding the presence or absence of loons and loon productivity, and, educate the public regarding loon ecology and preservation. This dissertation represents the work completed to fulfill the requirements for the Doctor of Philosophy degree in Natural Resources Management at the University of New …

The Nature Of Dissection: Exploring Student Conceptions, Katharine York

Doctoral Dissertations

The model of conceptual change in science describes the process of learning as a complete restructuring of knowledge, when learners discover or are shown more plausible, intelligent alternatives to existing conceptions. Emotions have been acknowledged as part of a learner's conceptual ecology, but the effects of emotions on learning have yet to be described. This research was conducted to examine the role that emotions have on learning for thirteen high school students, as they dissected cats in a Human Anatomy and Physiology class. The project also investigated whether a student's emotional reactions may be used to develop a sense of …

Creativity Or Creativities: A Study Of Domain Generality And Specificity, Zorana Ivcevic

Doctoral Dissertations

A series of studies investigated domain generality and specificity in creativity. Preliminary studies developed behavior report measures based on act-frequency and life-space approaches. The main studies examined two aspects of generality and specificity in creativity. A first group of studies analyzed the structure of creative behavior and the second group of studies concerned personality correlates of creativity. Dimensions of creative behavior were identified in a factor analysis of behavior reports and referred to creative life-style, arts, and intellectual achievement. Moreover, these dimensions were replicated in college students and professional adults. Groups of individuals with similar patterns of behavior were identified …

On The Role Of High Frequency Waves In Ocean Altimetry, Douglas C. Vandemark

Doctoral Dissertations

This work mines a coastal and open ocean air-sea interaction field experiment data set where the goals are to refine satellite retrieval of wind, wind stress, and sea level using a microwave radar altimeter. The data were collected from a low-flying aircraft using a sensor suite designed to measure the surface waves, radar backscatter, the atmospheric flow, and turbulent fluxes within the marine boundary layer. This uncommon ensemble provides the means to address several specific altimeter-related topics. First, we examine and document the impact that non wind-driven gravity wave variability, e.g. swell, has upon the commonly-invoked direct relationship between altimeter …

Pole -Mounted Sonar Vibration Prediction Using Cmac Neural Networks, Chunshu Zhang

Doctoral Dissertations

The efficiency and accuracy of pole-mounted sonar systems are severely affected by pole vibration, Traditional signal processing techniques are not appropriate for the pole vibration problem due to the nonlinearity of the pole vibration and the lack of a priori knowledge about the statistics of the data to be processed. A novel approach of predicting the pole-mounted sonar vibration using CMAC neural networks is presented. The feasibility of this approach is studied in theory, evaluated by simulation and verified with a real-time laboratory prototype, Analytical bounds of the learning rate of a CMAC neural network are derived which guarantee convergence …

Vector Polarization Observables Of The Deuteron And A New Measurement Of The Magnetic Dipole Form Factor G(M), Peter Joseph Karpius

Doctoral Dissertations

A measurement of the vector analyzing power Te11 in elastic electron-deuteron scattering has been performed at the MIT-Bates Linear Accelerator Center using a polarized electron beam, an internal polarized atomic deuterium target, and the symmetric BLAST (Bates Large Acceptance Spectrometer Toroid) detector in the Bates South Hall Ring. The beam helicity dependent target vector asymmetries, simultaneously measured in both sectors of BLAST, allow the extraction of Te11 . To the best of our knowledge this is the first such use of a polarized target to determine Te11 . Furthermore, these data, when combined with measurements of A(Q2) and the target …

Characterization Of The Major Extrapallial Fluid Protein Of The Mollusc, Mytilus Edulis: Implications For Function, Yan Yin

Doctoral Dissertations

The major protein component of the extrapallial (EP) fluid of the mollusc Mytilus edulis, named the EP protein, has been previously isolated and partially characterized. It has been proposed to play an important role in shell mineralization because of its intriguing property of Ca2+ -binding induced self-assembly.

This dissertation reports on the characterization of the primary structure of the EP protein by RT-PCR and cDNA sequencing methods. The EP protein is comprised of 213 amino acids post cleavage of a signal peptide of 23 amino acids, and is rich in His, Glu and Asp residues. The consensus site of N-glycosylation …

Applications Of Fluorescence Detected Sedimentation I Studying The Thermodynamic Impact Of Valence In Non-Ideal Solutions Ii High Affinity Interactions And Biological Media, Rachel R. Kroe

Doctoral Dissertations

The recent addition of the fluorescence detection optical system (FDS) to the currently available absorbance and interference optical systems on the analytical ultracentrifuge has greatly expanded the wide application of this technique. The new FDS is able to detect very low concentrations of fluorophore allowing the study of high affinity interactions (Kd ∼ pM) not previously accessible with the absorbance optics. The types of high affinity interactions that can be explored include drug-protein interactions, lipid-receptor interactions, DNA-protein interactions and protein-protein interactions. Selective labeling of one or both of the macromolecules can allow elegant dissection of complex assemblies. The only limiting …

Faculty Perceptions Of The Effects Of Collective Bargaining Agreements On Their Professional Roles: The New England Public Higher Education Experience, Nancy J S Hamer

Doctoral Dissertations

This study, a combination of quantitative and artifact analysis, examined how New England public college and university faculty perceived their professional concerns were affected by working under a collective bargaining agreement. The professional concerns, derived from the pertinent literature, included the following: the ability of the faculty to effectively influence who joined the faculty ranks; their powers to determine the curriculum, with their related instructional practices/delivery systems, and the setting of degree requirements; determining their teaching, scholarship, and service requirements; assuring the exercise of academic freedom, and reasonable shared governance.

Coupled with these professional concerns were three research questions that …

Mitigating Alkali Silica Reaction In Recycled Concrete, Xinghe Li

Doctoral Dissertations

Concrete made with recycled concrete aggregate (RCA) that had shown alkali silica reaction (ASR) distress was evaluated. It was found that ASR mitigation was needed to prevent continued expansion. Several mitigation methods were evaluated and compared to conventional concrete using the testing procedures of ASTM C 1260/1567 and ASTM C 1293. Pore solution analysis and Thermal Gravimetric Analysis (TGA) were also conducted.

It was found that fly ash, silica fume and ground granulated blast furnace slag (GGBFS) were effective in mitigating ASR in RCA concrete. Compared to conventional concrete, slightly higher dosages were typically required. The ASTM C 1260/1567 test …

The Process Of Integration And The Concept Of Integral: How Does Success With Applications And Comprehension Of Underlying Notions Such As Accumulation Relate To Students' Mathematical Fluency, Mariana Montiel

Doctoral Dissertations

At the end of the standard first calculus course, the student is expected to learn the Fundamental Theorem of Calculus, and to be able to use the integral to produce new functions, or numbers which, they are told, represent the "area under the curve". At the beginning of the standard second calculus course, students are expected to generalize their knowledge, and use the integration process to generate solids of revolution, surface areas, arc length and work, among other applications. Looking at students' success or failure in these endeavors, it was detected that there are marked differences in an aspect that, …

Sensing The Human Alpha Rhythm Using A Non-Contact Electroencephalographic (Eeg) Electrode, Wayne J. Smith Ii.

Doctoral Dissertations

The electroencephalogram is the recording of bioelectrical potentials on the scalp due to neural current sources in the brain and are typically recorded using wet surface electrodes that make ohmic contact with the scalp surface using an electrolyte gel. Unfortunately, wet electrodes are intrusive to the user, problematic for EEG studies requiring high spatial resolution, and are unsuitable for long-duration EEG recordings. Wet electrodes ultimately limit spatial resolution since the gel can short neighboring electrodes. They also do not meet long-duration recording demands since the gel can dry out over time.

This dissertation explores the feasibility of measuring the EEG …

Nonlinear Dynamics Of Blood Flow In Simple Microvascular Networks, Fan Wu

Doctoral Dissertations

It has been found that spontaneous oscillations of nodal pressures, hematocrit, and blood velocity can occur in microvascular networks in the absence of biological control. In this paper, both analytical and numerical methods have been used to investigate the nonlinear dynamics of microvascular blood flow in simple networks. First, the steady state solutions for the system are found. Then the governing coupled PDE's are transformed into state dependent time delay differential equations, DDE's. The DDE's are then linearized about a steady state and normalized.

The characteristic equation for the network is found by assuming the linearized DDE's have a nontrivial …

Tourism Of A Different Kind In "God's Own Country" : A Critical Hermeneutic Exploration Of Socioeconomic Development In Kerala, India, Ayliffe B. Mumford

Doctoral Dissertations

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Cad Model Extraction Of Pcb Signal Discontinuity Using A Circuit Extraction Approach Based On Mixed-Potential Integral Equation Formulation, Shaofeng Luan

Doctoral Dissertations

"In high-speed digital design, signal via transitions on printed circuit boards (PCBs) are becoming an important signal integrity issue. Efficient and accurate models for via transitions are necessary to analyze high bit-rate digital circuit system. The circuit extraction approach based on a mixed-potential integral equation formulation (CEMPIE) is an extension of the Partial Element Equivalent Circuit approach (PEEC) to general multi-layered media. CEMPIE was further developed to include the horizontal current components on the vertical surface and extended to model the discontinuities on multilayer PCBs. A procedure of building SPICE models for signal via transitions between printed circuit board layers …

Polymer-Based Wide-Angle Micro -Optic Lens System With Dynamically Variable Focal Length And Field Of View, Mangilal Agarwal

Doctoral Dissertations

A novel polymer-based integrated wide-angle dynamic micro-optical lens system that can provide variable focal length and field of view (FOV) with large numerical aperture is designed, fabricated, and tested for its optical characteristics.

Initial experiments were conducted using static glass lenses to test for configuration of lenses that could provide wide FOV. From these initial experiments, it was found that the higher FOV could be achieved with double concave (DCV) lenses compared to double convex (DCX) lenses of the same focal length. Further, it was observed that increasing the number of DCV lenses increases FOV. Thus, an integrated dynamic polymer …

Layer-By-Layer Self -Assembly For Enzyme And Dna Encapsulation And Delivery, Amish Patel

Doctoral Dissertations

Thin wall microcapsules were formed via Layer-by-Layer Self-Assembly of alternate adsorption of oppositely charged polyelectrolyte on microcores. After the core dissolution, empty polymeric shells with 20–25 nm thick walls were obtained. These microcapsules were loaded with Myoglobin, Hemoglobin and Glucose Oxidase by opening capsule pores at low pH and closing them at higher pH. The native structure of the enzyme was not affected due to different treatments. Biocompatible nanoshells were also prepared for encasing DNA. Using the same Layer-by-Layer Self-Assembly approach nanoparticle were constructed containing DNA as one of the layers. The nanoparticles of different architecture were used to deliver …

Layer-By-Layer Nanoassembly Combined With Microfabrication Techniques For Microelectronics And Microelectromechanical Systems, Jingshi Shi

Doctoral Dissertations

The objective of this work is to investigate the combination of layer-by-layer self-assembly with microfabrication technology and its applications in microelectronics and MEMS.

One can assemble, on a standard silicon wafer, needed multilayers containing different nanoparticles and polymers and then apply various micromanufacturing techniques to form microdevices with nanostructured elements.

Alternate layer-by-layer self-assembly of linear polyions and colloidal silica at elevated temperatures have been firstly studied by QCM and SEM. LbL self-assembly and photolithography were combined to fabricate an indium resistor. The RTA method was employed in the fabrication. Hot-embossing technique as a reasonably fast and moderately expensive technique was …

The Relationships Of Teachers' Levels Of Technology Integration On Student Achievement In Reading And Mathematics, Valerie S. Fields

Doctoral Dissertations

The purpose of this study was to determine to what extent the level of technology integration of fourth and eighth grade teachers in eleven rural school districts in northeastern Louisiana related to student achievement in reading and mathematics.

The sample consisted of 123 fourth and eighth grade teachers and their students from the eleven rural school districts in northeastern Louisiana. Fifty-eight percent of the teachers represented the fourth grade and 42% of the teachers represented the eighth grade. The teachers served a school age population in which 20% or more was from families with incomes below the poverty line.

Mean …