“Design And Verification Of A Reusable Self-Reconfigurable Gate Array Architecture, Gabriel Cozmin Chereches

Masters Theses

This thesis presents the design and verification of a Self-Reconfigurable Gate Array architecture (SRGA-UT) created for reuse, and available with a step-by-step tutorial and comprehensive documentation. The original SRGA [1], created at the University of Southern California, is an innovative architecture for a reconfigurable device that allows single cycle context switching and single cycle random access to a unified on-chip configuration/data memory. The key architecture that enables the above two features is the use of a mesh of trees based interconnect with logic cells and memory blocks at the leaf nodes and identical switches at the parent nodes.

The SRGA-UT …

Topology Optimization Of Carbon Nanotube Reinforced Polymer Damping Structures, Seshadri Mohan Varma Damu

Masters Theses

Topology optimization has been successfully used for improving vibration damping in constrained layer damping structures. Reinforcing carbon nanotubes in a polymer matrix greatly influence the mechanical properties of the polymer. Such nanotube-reinforced polymers (NRP) can be used to further enhance the damping properties of the constrained layer structures. In this work, topology optimization is performed on constrained damping layer structures using NRP in order to maximize the loss factor for the first resonance frequency of the base beam. In addition to the material fractions of the NRP and elastic material, the volume fraction of the nanotubes in the polymer is …

Characterizing Turbulence Structure Along Woody Vegetated Banks In Incised Channels: Implications For Stream Restoration, Frank James Dworak

Masters Theses

The impacts of urbanization have modified natural watersheds and stream hydraulic, hydrologic, and geomorphic processes that have lead to geomorphic and ecological disturbances in natural stream systems. These alterations have resulted in channel incision and the loss of channel-scale hydraulic characteristics responsible for initiating and maintaining pool-riffle bedforms, which are capable of supporting diverse biological stream ecosystems. Through the use of FLOW-3D, a 3-dimensional computational fluid dynamics model, three scenarios of an urban, incised, and channelized stream were simulated to characterize the turbulent, hydraulic structure during bankfull discharge. The simulations were conducted with trees inhibiting bankfull flow (representing the channel’s …

Hardware Design And Implementation Of Role-Based Cryptography, Scott Edward Fields

Masters Theses

Traditional public key cryptographic methods provide access control to sensitive data by allowing the message sender to grant a single recipient permission to read the encrypted message. The Need2Know® system (N2K) improves upon these methods by providing role-based access control. N2K defines data access permissions similar to those of a multi-user file system, but N2K strictly enforces access through cryptographic standards. Since custom hardware can efficiently implement many cryptographic algorithms and can provide additional security, N2K stands to benefit greatly from a hardware implementation. To this end, the main N2K algorithm, the Key Protection Module (KPM), is being specified in …

Bench Scale Evaluation Of Dense Ceramic Membranes For Production Of High Purity Hydrogen From Gasification, Binay Kumar Singh

Masters Theses

Gasification for production of hydrogen and other useful gases, has achieved increasing importance in recent years. The reactions involved in gasification are favored at high temperatures and they are also limited by thermodynamic equilibrium. The development of membranes which can separate these gases under gasifier exit gas condition will significantly improve process efficiency and economics and simultaneously provide for the recovery of valuable gases. The availability of a membrane with adequate hydrogen selectivity and good thermal and mechanical stability is the key for the successful application of membrane technology in hydrogen production and separation. This work introduces a special method …

Performance Study Of Hybrid Spread Spectrum Techniques, Yachna Sharma

Masters Theses

This thesis focuses on the performance analysis of hybrid direct sequence/slow frequency hopping (DS/SFH) and hybrid direct sequence/fast frequency hopping (DS/FFH) systems under multi-user interference and Rayleigh fading. First, we analyze the performance of direct sequence spread spectrum (DSSS), slow frequency hopping (SFH) and fast frequency hopping (FFH) systems for varying processing gains under interference environment assuming equal bandwidth constraint with Binary Phase Shift Keying (BPSK) modulation and synchronous system. After thorough literature survey, we show that hybrid DS/FFH systems outperform both SFH and hybrid DS/SFH systems under Rayleigh fading and multi-user interference. Also, both hybrid DS/SFH and hybrid DS/FFH …

Managing The Remaining Service Life Of The T-34c Aircraft, John Howard Rousseau

Masters Theses

The T-34C Airplane has been the primary trainer aircraft of the United States Navy for more than twenty-five years and is reaching the end of its service life. The Navy has delayed the procurement of the replacement T-6A Texan II aircraft for five years, yet does not expect the future training requirements to diminish. This delay in T-6A procurement along with recent observed increases in primary trainer aircraft usage have resulted in the need for the Navy to pay considerable attention to the remaining service life of the T-34C aircraft.

This thesis will discuss the methodology used to determine future …

A Comparison Of The Sensor Brick Concept As A Modular System Architecture To The Realtime Control System As The Operational Architecture, James Robert Wilson

Masters Theses

This thesis describes the application of modular design into an intelligent mobile robotic system. The Sensor Brick System, a mobile robotic system infused with artificial intelligence, is derived through the concept and application of modular design. Modular design drives the system’s characterization by defining, identifying and selecting the essential composite of sub-systems that form the system architecture. The principles of modular design designate grouping the technologies into modules that facilitate maintenance of the system components and allow the rapid integration of future technological developments. Developing the operational control of the system requires an examination and comprehension of the theories of …

Linking Channel Stability And Bed Sediment Characteristics To Biological Integrity In Tennessee Ridge And Valley Streams, Kelley H. Williams

Masters Theses

Streambed sedimentation has plagued waterways since the beginning of civilization, whether as a natural flow process or human disturbances on the landscape in more recent times. Due to the continual degradation in the quantity and diversity of aquatic organisms within streams, the issue has finally surfaced as a significant concern. The need to develop better Total Maximum Daily Load (TMDL) assessment tools to link sediment impairment to biological integrity was the driving force behind this study.

Within the Ridge and Valley Ecoregion, 76 stream reaches were analyzed to investigate the impacts of stability issues and bed sediment characteristics on stream …

Kinetics Of Cellulose Dissolution In N-Methyl Morpholine-N-Oxide And Evaporative Processes Of Similar Solutions, John William Tierney

Masters Theses

The lyocell process is an environmentally friendly process for producing regenerated cellulose fibers, but is not entirely understood. The lyocell process uses the hygroscopic solvent N-methyl morpholine N-oxide (NMMO) to dissolve cellulose; the resulting solution is often termed a lyocell solution [1-4]. It is the objective of this study to better understand the process by which cellulose dissolves and the nature of lyocell solutions. By observing the disappearance of cellulose fibers into the solvent, rate data may be obtained from which kinetic parameters may be developed. Additionally an independent method for determining the concentration of cellulose in lyocell solutions was …

Flight Testing Quadeye The First Night Vision Helmet Mounted Cueing System For Fixed Wing Jet Aircraft, Timothy Ghannon Burton

Masters Theses

In 2002 the United States Navy introduced helmet mounted cueing systems (HMCS) into tactical jet operations. As aircrews have become more reliant on their HMCS the requirement for a night vision capable cueing system has risen to the forefront of HMCS technology. One proposed solution to this requirement was Quadeye. Quadeye is a wide-angle (100deg field of view) four cathode-ray tube system with injected Joint Helmet Mounted Cueing video. The Navy flew 8 evaluation sorties from March to August 2005, in the F-18 A-F fighter aircraft. The goal of this limited scope effort was to answer four questions:

1. Does the …

   ---

   Go to article

An Experimental Study Of Axisymmetric Cavity Oscillations In Low Speed Incompressible Flow, Jeremy David Brice Smith

Masters Theses

This study is the latest increment of an ongoing research effort at the University of Tennessee Space Institute with the goal of accomplishing a greater understanding of cavity instabilities and or making use of the instabilities to amplify their effects on the flows. An experimental procedure was designed to examine the unsteady pressure pulses that occur when an incompressible fluid (water) flows through an axisymmetric cavity. The length to depth ratios (L/D) examined ranged from about 0.69 to about 6.2, and the average flow Reynolds numbers ranged from 0 to 1.2 million.

Results show that large amplitude oscillations are generated …

Comparative Properties Of Polymers Guiding The Development Of An Abdominal Aorta Model, Benjamin Michael Lamie

Masters Theses

Hemodynamics, the study of the forces involved in the circulation of blood, is an area that researchers have approached in various manners for many years. The study of how blood flows through arteries and veins as well as the effect of the composition of the blood has been defined and thoroughly characterized in past studies. Although in-depth studies have been performed on the flow characteristics of blood, most often the observations are made as the fluid flows through tubes composed of some rigid material. It is well known that the arteries and veins have a layered histology that show varying …

Viscosity Measurement Technique By Merging Liquid Drops Aboard The International Space Station, Daniel Aaron Lehman

Masters Theses

The efforts reported in this thesis has been to analyze the data from two "Fluid Merging Viscosity Measurement" experiments in order to validate this as a viable method for measuring the viscosity of fluids with known surface tensions. This method involves simultaneously using a numerical analysis code and experimental data to produce matching curves of contact radius versus time and from that a determination of viscosity. Two experiments that were performed, used different liquids (glycerin and 125 Poise silicon oil) and different size ratios between the two drops ( 1 to 1 and O. 3 3 to 1 respectively). The …

A Study Of Material Properties And Relevant Microstructure Parameters That May Influence The V50 Ballistic Limit Velocity Of Composite Ceramics, Adolphus Mcdonald

Masters Theses

The purpose of this research is to evaluate, compare, and correlate the microstructure and mechanical properties of a selected group of ceramic armor samples to the V₅₀ ballistic limit velocity. This study is to identify any relation between the desired material properties and the relevant microstructure parameters that significantly influence the ballistic limit velocity. The ceramic materials, silicon carbide and boron carbide, were produced and provided by five foreign companies. These companies were under contract by the United States Army, Research, Development, and Engineering Command to provide ceramic armor for comparative testing and material evaluation.

Ballistic testing was carried …

Design Of A Novel Reluctance Motor For Industrial Applications, Weston Clute Johnson

Masters Theses

A novel reluctance motor topology, termed the Johnson-Currie Reluctance Motor (JCRM), has been developed and described in this thesis. The JCRM topology and analysis is based upon the traditional switched reluctance motor (SRM) topology although there are significant modifications.

The flux path of the JCRM topology is such that it passes through the rotor and stator in three-dimensions. This topology with three dimensional flux paths allows for the removal of discrete stator windings giving rise to vastly superior maintance to the traditional SRM and arguably to most electric motors. In addition, the usage of three-dimensions for flux paths gives rise …

Synthesis, Microstructure, And Mechanical Behavior Of Fe-Cu Composites, Jin-Woo Jeon

Masters Theses

The synthesis, microstructure, and mechanical properties of ball-milled nanocrystalline (nc) Fe powder and immiscible Fe-Cu alloy composites are investigated in this thesis. Experimental approaches are described for the characterization of the grain size and hardness of nc Fe powders and the internal stress state of bulk Fe-Cu alloy composites are presented.

The grain size measurements of ball-milled Fe powders obtained from the XRD line broadening analysis (15 nm) and TEM observation (18 nm) showed good agreement between two results. From the nanoindentation tests, the hardness values of the ball-milled Fe powders were increased from 3.5 to 10.5 GPa as the …

Enhancing System-On-Chip Verification Using Embedded Test Structures, Wei Jiang

Masters Theses

In this project, we designed and implemented a System-on-Chip platform with embedded test structures. The baseline platform consists of a Leon2 CPU, AMBA on-chip bus, and an Advanced Encryption Standard decryption module. Reconfigurable test logic blocks were embedded to form the test structure that can be used in post-silicon debug and verification.

The System-on-Chip platform was designed at the register transistor level and implemented in an 180nm CMOS process. Test logic instrumentation was done with DAFCA, Inc. (Design Automation for Flexible Chip Architecture) pre-silicon tools. The design was then synthesized using the Synopsys Design Compiler and placed and routed using …

Comparison Of Microscopic Modalities For The 3d Model Reconstruction Of Nanodevices, Christopher Robert Kammerud

Masters Theses

As manufacturing capabilities push nanotechnology to smaller and smaller scales, novel inspection schemes must be developed to ensure product quality. The objective of our research was to implement, refine, and compare 3D reconstruction algorithms that could aid manufacturers in their ability to visualize and inspect nanodevices. Data was collected from three different microscopes: the atomic force microscope (AFM), the scanning electron microscope (SEM), and the laser scanning confocal microscope (LSCM). For each of these microscopes, a specific algorithm was implemented to generate 3D models from the raw microscope data. Scans from the AFM microscope give range information similar to laser …

A K-Epsilon Extension For Wall-Bounded Flows On The Broadband Aeroacoustic System Simulator, David González

Masters Theses

The turbulence modeling capabilities of the Broadband Aeroacoustic System Simulator (BASS), an experimental code developed at NASA Glenn Research Center, have been extended to include wall-bounded flow capabilities. This was done by first validating the code's viscous solving routines by comparing numerical solutions to known, simple analytic solutions. Finally, the dynamics of the wall shear flows were accounted for with the use of wall-damping functions incorporated into the turbulence model. The results for both viscous and turbulence routines agree well with published data.

Simulating Discriminatory Profiling, Oscar Neal

Masters Theses

There is a concern that racial profiling is being used to invoke searches and stops in spite of its violation of the fourth amendment. Simulation methods are used to study the correlation test of stops, searches and citations with race, age, and gender. The design uses sensitivity analysis of inputs to determine their relationship to outputs statistics of a police department's citations and stops. Experimental results are than used to verify and predict departmental bias. A simulation program written in Visual Basic is used as a tool to explore simulation techniques. A formulation of simulation uses in studying discriminatory profiling …

Experimental Aerodynamic Analysis Of A Wing-Flap System With Delta Vortex Generators, Charles Roy Mcconnell

Masters Theses

The principle idea upon which the use of vortex generators (VGs) is based has been to control flow separation. The characteristic of VGs has been used to improve lift and alter the stall characteristics of aircraft and has been a relatively common practice for many years. Due to the seemingly limitless range of VG geometries and arrangements, which are largely dependant upon the desired aerodynamic performance, there has been a broad investigation into VG application.

The purpose of this experimental investigation has been to collect data to be used to establish the effects of various delta shaped vortex generators (delta-VGs) …

Evaluation Of Mechanical Properties Of Recycled Aggregate Concrete, Sajjad Ali Khan

Masters Theses

The maintenance and repair work in the civil engineering infrastructures develops the production of huge wastes which causes the growth of waste piles, additional costs in construction projects and some environmental problems. If this waste is recycled and used again in construction projects, it will help to overcome the problems discussed earlier. Moreover, if natural aggregates are supplemented by recycled aggregate, it will preserve the natural resources and also put a pause in the deterioration of natural landscape.

This thesis addresses the importance of using recycled aggregate in concrete structures. Its practical feasibility in construction projects is studied in light …

Mixing Flow Structures Of Scalloped, Forced Lobed Mixers Using Piv And Plif Measuring Techniques, Nathan J. Cooper

Masters Theses

An Experimental study of internal forced lobed mixers similar to those used in jet aircraft engines is performed using whole field species concentration and velocity measuring techniques. Planar temperature and velocity measurements using Planar Laser Induced Fluorescence (PLIF) and 2D Particle Image Velocimetry (PIV) are performed for lobed, lobed scalloped and splitter mixers in aqueous solution. Specific emphasis is given to study scallops or notches cut into the mixer trailing edge and their role in mixing enhancement. Mixing is compared through velocity and species concentration measurements on axial and streamwise planes for the three dimensional, forced mixers in a confined …

Evaluation Of Mechanical Properties Of Self-Consolidating Concrete, Bhusan Basnet

Masters Theses

The concept of Self-Consolidating Concrete is a fresh and rapidly ramping technology in USA, but in some other continents such as Japan and Europe it is in fully fledged stage. The development of this technology has a high potential to economize construction minimizing labor, scheduled time and equipment eliminating consolidation process. In USA, construction professionals are reluctant to its in-effect application because of lack of deliberate and methodological steps for production and applications. The lack of study of its durability characteristics and confusion in design and production process are seems to be vital factors hindering full scale production and application …

Ductile Regime Nano-Machining Of Silicon Carbide, Biswarup Bhattacharya

Masters Theses

This thesis describes experimental work carried out to study the ability to ductile . single point diamond turn both polycrystal Silicon Carbide (SiC) and chemically vapor deposited (CVD) SiC. A Precitech diamond turning machine was used for ductile regime machining of polycrystal SiC at depths of 10 and 25 nm. The possibility of machining SiC in the ductile mode was substantiated by post process analysis of the chips collected during machining and the surface profiles. The force data obtained during machining was recorded and compared later with the different depth of cuts. An investigation into the ability to single point …

Determination Of Stiffness Matrix Of Tapered Roller Bearings For Vibration Models, Jeeva Kumar

Masters Theses

The stiffness matrix of tapered roller bearings under radial and axial load conditions was evaluated using an analytical model and an experimental approach. An experimental test system was designed and manufactured to determine the radial stiffness of the bearing under combined axial and radial load conditions. A second fixture was designed to measure the stiffness of the bearing under pure axial load conditions. The stiffness coefficients determined have been compared with those obtained from the analytical model, OEM (Original Equipment Manufacturer) data and ABAQUS model (finite element analysis software).

Guidelines To Select A Computerized Maintenance Management System, Dattaraj Kamalapurkar

Masters Theses

In today's highly competitive global economy, maintenance personnel are presented with more difficult challenges than at any previous point in time. In order to meet these challenges, many maintenance managers tend to rely . on Computerized Maintenance Management System (CMMS). When properly selected and implemented, CMMS is one of the most powerful cost reduction tools in any organization. However in reality, many CMMS implementations fail rather than achieve success. While there are many contributing factors, one major factor that greatly impacts successful implementation is selecting the right CMMS system. With more than 200 CMMS systems to choose from, selecting the …

A Dynamic Ampacity Model For The Testing Of Advanced Conductors, Matthew Benjamin Sooter

Masters Theses

Advanced Conductors are an intriguing new technology that promises to help the utility industry increase the transmission capacity available in the United States. Manufacturers of advanced conductors promise double the current carrying capacity of normal Aluminum Clad Steel Reinforced conductor through a combination of increased thermal limits and decreased thermal elongation.

This thesis will outline a control developed for the Power Line Conductor Accelerated Test Facility at Oak Ridge National Laboratory. This custom facility is designed for the testing and rapid aging of advanced overhead conductors as part of a U.S. Department of Energy initiative to assist the development and …

Optimization Of Dsss Receivers Using Hardware-In-The-Loop Simulations, Balbir Kaur Dhillon

Masters Theses

Over the years, there has been significant interest in defining a hardware abstraction layer to facilitate code reuse in software defined radio (SDR) applications. Designers are looking for a way to enable application software to specify a waveform, configure the platform, and control digital signal processing (DSP) functions in a hardware platform in a way that insulates it from the details of realization.

This thesis presents a tool-based methodolgy for developing and optimizing a Direct Sequence Spread Spectrum (DSSS) transceiver deployed in custom hardware like Field Programmble Gate Arrays (FPGAs). The system model consists of a tranmitter which employs a …