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Promoting Supportive Relationships In Youth Programs: A Self-Determination Theory Perspective, Mat Duerden, Ann Gillard Dec 2008

Promoting Supportive Relationships In Youth Programs: A Self-Determination Theory Perspective, Mat Duerden, Ann Gillard

Journal of Youth Development

Although research suggests that positive contact with non- parental adults is developmentally beneficial for youth; many adolescents do not have access to such relationships. It is important that adults structure existing relationships to optimize positive youth development. Relationships with adults, who support youth’s needs for autonomy, relatedness, and competence, provide youth with scaffolding as they navigate their way through adolescence. Self-Determination Theory offers a straight-forward approach to understanding the elements of contexts that best promote the development of supportive relationships. The purpose of this paper is to review the literature concerning youth-adult relationships, including their associated prevalence and developmental benefits …

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The Development Of Hyaluronic Acid Biomaterials For Vascular Tissue Engineering, Samir Ibrahim Dec 2008

The Development Of Hyaluronic Acid Biomaterials For Vascular Tissue Engineering, Samir Ibrahim

All Dissertations

Current vascular implant materials poorly interact with medial smooth muscle cells (SMCs) allowing the permanent loss of vascular elastin, eliminated by trauma or disease, a crucial element in maintaining the natural biomechanics of the blood vessel and overall vascular homeostasis. In addition, these materials insufficiently recruit vascular endothelial cells (ECs) to form a normally functional, confluent endothelium that acts as the interface between the blood and vascular tissue and regulates numerous vital vascular processes. As a result, the restenosis, or re-occlusion, rate within these devices has remained fairly high stimulating the investigation of numerous new materials capable of providing the …

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The Thermoelectric Properties Investigation Of X0.05Mo3Sb7-YTeY (X=Mn, Fe, Ni, Co; Y=1.5, 1.6, 1.7), Tim Holgate Dec 2008

The Thermoelectric Properties Investigation Of X0.05Mo3Sb7-YTeY (X=Mn, Fe, Ni, Co; Y=1.5, 1.6, 1.7), Tim Holgate

All Theses

With ever increasing energy costs, dwindling resources, and terms with the prefix 'green' filling headlines, the need for environmentally friendly energy sources has never been greater. Since the mid-20th century researchers have been pursuing greater efficiency in thermoelectric materials. Thermoelectric materials achieve energy conversion via the Seebeck effect (heat to electric power) and the Peltier effect (electricity to cooling power). Presented herein are the measured electrical and thermal transport properties and phenomenal analysis of the Ir3Ge7-type system: X0.05Mo3Sb7-yTey (X=Mn, Fe, Ni, Co; y=1.5, 1.6, 1.7) where 'X' are interstitially …

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Hydraulic Actuated Automotive Cooling Systems - Nonlinear Control And Test, John Wagner, M H. Salah, P M. Frick, D M. Dawson Dec 2008

Hydraulic Actuated Automotive Cooling Systems - Nonlinear Control And Test, John Wagner, M H. Salah, P M. Frick, D M. Dawson

Publications

The replacement of traditional automotive mechanical cooling system components with computer controlled servo-motor driven actuators can improve temperature tracking and reduce parasitic losses. The integration of hydraulic actuators in the engine cooling circuit offers greater power density in a smaller package space when compared with electric actuators. In this paper, a comprehensive nonlinear backstepping robust control technique is developed to regulate the engine coolant temperature by controlling a hydraulic coolant pump and radiator fan. An experimental test bench has been assembled to investigate the hydraulic automotive thermal system performance. Representative numerical and experimental results are presented and discussed. Overall, the …

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A Performance And Productivity Study Using Mpi, Titanium, And Fortress, Amy Apon, Chris Bryan, Wesley Emeneker Dec 2008

A Performance And Productivity Study Using Mpi, Titanium, And Fortress, Amy Apon, Chris Bryan, Wesley Emeneker

Publications

The popularity of cluster computing has increased focus on usability, especially in the area of programmability. Languages and libraries that require explicit message passing have been the standard. New languages, designed for cluster computing, are coming to the forefront as a way to simplify parallel programming. Titanium and Fortress are examples of this new class of programming paradigms. This papers presents results from a productivity study of these two newcomers with MPI, the de- facto standard for parallel programming.

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Magnetohydrodynamic Effects In Propagating Relativistic Jets: Reverse Shock And Magnetic Acceleration, Yosuke Mizuno, Bing Zhang, Bruno Giacomazzo, Ken-Ichi Nishikawa, Phillip E. Hardee, Shigehiro Nagataki, Dieter H. Hartmann Dec 2008

Magnetohydrodynamic Effects In Propagating Relativistic Jets: Reverse Shock And Magnetic Acceleration, Yosuke Mizuno, Bing Zhang, Bruno Giacomazzo, Ken-Ichi Nishikawa, Phillip E. Hardee, Shigehiro Nagataki, Dieter H. Hartmann

Publications

We solve the Riemann problem for the deceleration of an arbitrarily magne-tized relativistic flow injected into a static unmagnetized medium in one dimen-sion. We find that for the same initial Lorentz factor, the reverse shock becomes progressively weaker with increasing magnetization σ (the Poynting-to-kinetic energy flux ratio), and the shock becomes a rarefaction wave when σ exceeds a critical value, σc, defined by the balance between the magnetic pressure in the flow and the thermal pressure in the forward shock. In the rarefaction wave regime, we find that the rarefied region is accelerated to a Lorentz factor that is significantly …

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Novel Lactide Derived Polymers; Synthesis, Properties And Applications, Dahlia Haynes Dec 2008

Novel Lactide Derived Polymers; Synthesis, Properties And Applications, Dahlia Haynes

All Dissertations

This dissertation primarily encompasses the synthesis, characterization, properties and discussion of applications for lactide derived polymers. The methodology focuses on altering polylactide's (PLA's) dynamic and physical properties increasing its broad market utility in both traditional and non-traditional applications. The fundamentals of this work include understanding and enhancing the polymer chemistry and materials related processes through the use of copolymerization, fluorination, composite chemistry and materials science.
The first chapter discusses the important of this research with emphasis on current world issues that focuses on the feasibility of renewable resources and sustainability implementation. Modification of renewable resource materials like lactic acid is …

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'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma Dec 2008

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma

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This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for …

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Real-Time Automatic Linear Feature Detection In Images, Guang Zeng Dec 2008

Real-Time Automatic Linear Feature Detection In Images, Guang Zeng

All Dissertations

Linear feature detection in digital images is an important low-level operation in
computer vision that has many applications. In remote sensing tasks, it can be used
to extract roads, railroads, and rivers from satellite or low-resolution aerial images,
which can be used for the capture or update of data for geographic information and
navigation systems. In addition, it is useful in medical imaging for the extraction of
blood vessels from an X-ray angiography or the bones in the skull from a CT or MR
image. It also can be applied in horticulture for underground plant root detection in
minirhizotron images. …

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Economic Analysis Of Adoption Of Water-Saving Land Improvements In Northern China, Xuanwen Wang Dec 2008

Economic Analysis Of Adoption Of Water-Saving Land Improvements In Northern China, Xuanwen Wang

All Dissertations

Determinants for farmers' choice of water-saving land improvements in Northern China are analyzed with a sample survey of 401 villages. The analysis focuses on two aspects of adoption, whether or not to adopt and if a technology is adopted, how much land to which to apply the technology. In the first stage, 'whether to adopt', multinomial logit models are applied to analyze the discrete choice of alternative land improvement strategies. In the second stage of adoption, 'how much to adopt', both sample selection models and OLS models are utilized to measure the adoption extent of field leveling, use of borders, …

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Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui Dec 2008

Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui

All Dissertations

The current tissue engineering paradigm is that successfully engineered thick tissues must include vasculature. As biological approaches alone such as VGEF have fallen short of their promises, one may look for an engineering approach to build microvasculature. With the advent of cell printing, one may be able to build precise human microvasculature with suitable bio-ink. Human Microvascular Endothelial Cells (HMVEC) and fibrin were studied as bio-ink for microvasculature construction. Endothelial cells are the only cells to compose the human capillaries and also the major cells of blood vessel intima layer. Fibrin has been already widely recognized as tissue engineering scaffold …

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Fabrication And Optical Properties Of Noble Metal Nanostructures, Mark Kinnan Dec 2008

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 …

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Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash Dec 2008

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 …

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Calculations Of Diffusion In Fcc Binary Alloys Using On-The-Fly Kinetic Monte Carlo, Erdi Bleda Dec 2008

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 …

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Fluorescent Conjugated Polymer Dots For Single Molecule Imaging And Sensing Applications, Changfeng Wu Dec 2008

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 …

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Synthesis, Characterization, And Application Of Ag Nanostructures, Stephen Hudson Dec 2008

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 …

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Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy Dec 2008

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 …

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Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane Dec 2008

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 …

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Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee Dec 2008

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 …

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Topographic Analysis And Predictive Modeling Using Geographic Information Systems, Steven Hall Dec 2008

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 …

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Two Categories Of Refutation Decision Procedures For Classical And Intuitionistic Propositional Logic, Edward Doyle Dec 2008

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 …

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Computional Modeling Of Precision Molding Of Aspheric Glass Optics, Balajee Ananthasayanam Dec 2008

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 …

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Synthesis And Characterization Of Biodegradable Polyurethanes For Biomedical Application, Changhong Zhang Dec 2008

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

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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 …

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Population Growth And Planned Birth Policy, Yigang Zhang Dec 2008

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 …

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Hybrid Bond-Order Potential For Silicon, Suleiman Oloriegbe Dec 2008

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 …

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Characterization Of Campus Parking Lot Stormwater And Remediation Of Risks Using Constructed Wetland Treatment Systems, Andrew Mcqueen Dec 2008

Characterization Of Campus Parking Lot Stormwater And Remediation Of Risks Using Constructed Wetland Treatment Systems, Andrew Mcqueen

All Theses

Campus parking lot stormwater (CPLSW) runoff mobilizes a variety of constituents from vehicular and atmospheric deposition that may pose risks to receiving aquatic systems. The overall objective of this research was to provide an approach for risk characterization, toxicity identification, and remediation of constituents of concern in CPLSW. The specific objectives of this research were to: (1) Characterize campus parking lot stormwater (CPLSW) to discern the constituents of concern present in these waters; (2) Perform TIE manipulations to identify possible fractions of concern in CPLSW, and; (3) Evaluate the performance of a pilot-scale constructed wetland treatment system (CWTS) designed to …

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Optimal And Heuristic Resource Allocation Policies In Serial Production Systems, Ramesh Arumugam Dec 2008

Optimal And Heuristic Resource Allocation Policies In Serial Production Systems, Ramesh Arumugam

All Theses

We have studied the optimal server allocation policies for a tandem queueing system under different system settings. Motivated by an industry project, we have studied a two stage tandem queueing system with arrival to the system and having two flexible servers capable of working at either of the stations. In our research, we studied the system under two different circumstances: modeling the system to maximize throughput without cost considerations, modeling the system to include switching and holding costs along with revenue for finished goods. In the maximizing throughput scenario, we considered two different types of server allocations: collaborative and non-collaborative. …

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Independent Torque Distribution Management Systems For Vehicle Stability Control, Indrasen Karogal Dec 2008

Independent Torque Distribution Management Systems For Vehicle Stability Control, Indrasen Karogal

All Theses

Vehicle Dynamics Control (VDC) systems, also called Electronic Stability Control (ESC) systems, are active on-board safety systems intended to stabilize the dynamics of vehicle lateral motion. In so doing, these systems reduce the possibility of the driver's loss of control of the vehicle in some critical or aggressive maneuvers. One approach to vehicle dynamics control is the use of appropriate drive torque distribution to the wheels of the vehicle. This thesis focuses on particular torque distribution management systems suitable for vehicles with independently driven wheels.
In conducting this study, a non-linear seven degree-of-freedom vehicle model incorporating a non-linear tire model …

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Three Dimensional Visualization Of Fire Spreading Over Forest Landscapes, Brian Williams Dec 2008

Three Dimensional Visualization Of Fire Spreading Over Forest Landscapes, Brian Williams

All Theses

Previous studies in fire visualization have required high end computer hardware and specialized technical skills. This study demonstrated fire visualization is possible using Visual Nature Studio and standard computer hardware. Elevation and vegetation data were used to create a representation of the New Jersey pine barren environment and a forest compartment within Hobcaw Barony. Photographic images were edited to use as image object models for forest vegetation. The FARSITE fire behavioral model was used to model a fire typical of that area. Output from FARSITE was used to visualize the fire with tree models edited to simulate burning and flame …

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The Courage And Endurance To Remain In His Own Country And Fight The Battle Out: Donald Davidson And The South, 1893-1968, Michael Sisk Dec 2008

The Courage And Endurance To Remain In His Own Country And Fight The Battle Out: Donald Davidson And The South, 1893-1968, Michael Sisk

All Theses

This thesis examines the life of Donald Grady Davidson (1893-1968) and the forces - external and internal - that drove him to contribute to I'll Take My Stand: The South and the Agrarian Tradition, in 1930 and remain an avid apologist for Southern Agrarianism for the remainder of his life. Davidson, who began his literary career as a devotee of modernism, opposed much of his native culture yet suddenly changed directions around 1925 and embraced the distinctiveness of his Southern heritage. This thesis argues that events surrounding the Scopes Trial in 1925 caused Davidson to reevaluate his position on the …

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