Engineering Commons^™

Calculations Of The Interactions Of Energetic Ions With Materials For Protection Of Computer Memory And Biological Systems, Myung-Hee Y. Kim

Dissertations, Theses, and Masters Projects

Theoretical calculations were performed for the propagation and interactions of particles having high atomic numbers and energy through diverse shield materials including polymeric materials and epoxy-bound lunar regolith by using transport codes for laboratory ion beams and the cosmic ray spectrum. Heavy ions fragment and lose energy upon interactions with shielding materials of specified elemental composition, density, and thickness. A fragmenting heavy iron ion produces hundreds of isotopes during nuclear reactions, which are treated in the solution of the transport problem used here. A reduced set of 80 isotopes is sufficient to represent the charge distribution, but a minimum of …

Compensation And Characterization Of Gallium Arsenide, Randy A. Roush

Electrical & Computer Engineering Theses & Dissertations

The properties of transition metals in gallium arsenide have been previously investigated extensively with respect to activation energies, but little effort has been made to correlate processing parameters with electronic characteristics. Diffusion of copper in gallium arsenide is of technological importance due to the development of GaAs:Cu bistable photoconductive devices. Several techniques are demonstrated in this work to develop and characterize compensated gallium arsenide wafers. The material is created by the thermal diffusion of copper into silicon-doped GaAs. Transition metals generally form deep and shallow acceptors in GaAs, and therefore compensation is possible by material processing such that the shallow …

A Nonlinear Dynamic Method For Supporting Large-Scale Decision-Making In Uncertain Environments, Wayne Woodhams

Engineering Management & Systems Engineering Theses & Dissertations

This research developed a methodology for supporting decision making by reducing uncertainty in decision environments which are too large, dynamic and complex to be treated by traditional quantitative and simulation techniques. These environments are complex because of the free choice associated with human involvement, and the existence of a large number of interrelated factors which influence the outcomes of the decision process. They are dynamic because the ground rules affecting those interrelationships are constantly changing. Uncertainty cannot be treated probabilistically, since identification of a full set of outcomes and factors of influence is not possible.

The venue for the investigation …

Comparing Traditional Statistical Models With Neural Network Models: The Case Of The Relation Of Human Performance Factors To The Outcomes Of Military Combat, William Oliver Hedgepeth

Engineering Management & Systems Engineering Theses & Dissertations

Statistics and neural networks are analytical methods used to learn about observed experience. Both the statistician and neural network researcher develop and analyze data sets, draw relevant conclusions, and validate the conclusions. They also share in the challenge of creating accurate predictions of future events with noisy data.

Both analytical methods are investigated. This is accomplished by examining the veridicality of both with real system data. The real system used in this project is a database of 400 years of historical military combat. The relationships among the variables represented in this database are recognized as being hypercomplex and nonlinear.

The …

Iron Phosphate Glasses As A Potential Nuclear Waste Disposal Medium, Melissa G. Mesko

Masters Theses

”Phosphate glasses containing large amounts of Fe₂O₃ (up to 43wt%) were studied to determine their potential suitability as nuclear waste disposal glasses for high level radioactive wastes containing large concentrations of iron oxide, phosphate, and fluoride compounds. Glass formation and chemical durability was the prime focus of this study, while properties such as density, thermal expansion, dilatometric softening temperature, and devitrification temperature were examined as well. It was found that large amounts of simulated nuclear waste material (up to 44.4wt% Cs₂O or 37.5wt% SrO) could be incorporated into the base iron phosphate glass while retaining …

Effects Of Specimen Size Reduction On The Transition Curve Of The Charpy V-Notch Impact Test, Lonnie Eugene Schubert

Masters Theses

"This study was undertaken to correlate the impact properties of ASTM standard full size Charpy V-notch impact specimens to the impact properties of subsize specimens. An ASTM A533-B quenched and tempered plate steel was examined. The fine grained martensitic material had a coarse prior austenite grain size, which resulted in a low upper shelf energy for this material. Three sizes of specimens were included. Specimens were irradiated in the TRIGA Reactor Facility operated by the U. S. Geological Survey in Denver, Colorado, to 1 x 10¹⁹ n/cm² (E > 1 MeV) at 150°C (302°F). Unirradiated and irradiated specimens were …

Eigenproperties Of Nonclassically Damped Dynamic Systems, Daniel Patrick Malone

Masters Theses

"This thesis develops perturbation series solutions for the eigenvalues and eigenvectors of nonclassically damped dynamic systems for the case where the unperturbed system has repeated eigenvalues. The case of repeated eigenvalues is much more complicated than the case of perturbing a system with distinct eigenvalues. Because of this difficulty, only a specific category of dynamic systems with repeated eigenvalues is addressed. Namely, only those systems that when perturbed have series solutions of the form of a power series. This category of systems can be easily identified by an a priori check developed in the application section of this thesis. The …

Nozzle Flow With Vibrational Nonequilibrium, John Gary Landry

Mathematics & Statistics Theses & Dissertations

Flow of nitrogen gas through a converging-diverging nozzle is simulated. The flow is modeled using the Navier-Stokes equations that have been modified for vibrational nonequilibrium. The energy equation is replaced by two equations. One equation accounts for energy effects due to the translational and rotational degrees of freedom, and the other accounts for the affects due to the vibrational degree of freedom. The energy equations are coupled by a relaxation time which measures the time required for the vibrational energy component to equilibrate with the translational and rotational energy components. An improved relaxation time is used in this thesis. The …

Thermoplastic Composites Of Recycled High Density Polyethylene And Recycled Tire Particles, James N. Mckirahan Jr.

Masters Theses

This study identified the mechanical properties and processibility of composite materials of recycled high density polyethylene (HDPE), recycled rubber tire particles, and/or ethyl co-vinyl acetate and poly (e-caprolactone). The composites were processed using a single screw extrusion system.

Three groups of experiments were conducted, on the composites in their extruded form to investigate the mechanical properties of ultimate tensile strength, percent elongation, and hardness. The first experiment investigated the effect of recycled rubber particle concentration in the composites up to 25 percent. The second experiment investigated the effect of recycled rubber particle size on the composites of recycled HDPE and …

Investigation Of The Relationship Between Fuel Injection Nozzle Roto Flow And Hydra Flow And The Engine Torque Of A Diesel Engine, Guang Jin

Dissertations and Theses @ UNI

The purpose of this study was to investigate the possibility of reducing diesel engine torque variation by optimizing fuel injection nozzle tip configuration. In order to reduce engine torque variation, test runs were conducted to determine whether fuel injection nozzles affected diesel engine torque. There was a further effort to determine whether a correlation existed between the fuel injection nozzle roto flow and hydra flow, and the engine torque at specified engine speeds.

Engines installed in cotton pickers and tractors were used for this study. Engines, five from the cotton picker and five from the tractor group were chosen randomly …

Perceived Importance Of Iso 9000 Factors As Indicators Of Quality In Industrial Technology Related Programs At Four-Year State Regional Universities, Floyd L. Olson

Dissertations and Theses @ UNI

Industry has often used a quality standard known as ISO 9000. No evidence has been located demonstrating the applicability of an industrial quality model to a singular academic department. The problem of this study was to determine if the guidelines for ISO 9004-2 could have been considered appropriate for Industrial Technology related programs and how they could have been used to indicate quality within such programs.

The purpose of this study was to seek knowledge relating the importance of ISO 9004-2 guidelines to audit and/or improve the quality management of Industrial Technology related departments at 4-year state regional universities. This …

An Analysis Of The Use Of Programmable Controllers To Control An In Situ Leach Mine Wellfield, Jimmy W. Stokey

Dissertations and Theses @ UNI

In situ mining is a relatively new method that has the potential of recovering a variety of minerals. This process is quickly becoming an alternative to conventional mining techniques that are environmentally unsound. Two problems associated with in situ mining are, the amount of waste water generated by the process (bleed) and the uncontrolled migration of lixiviant outside the production zone (an excursion).

The purpose of this study was to determine if in situ mining processes could be monitored and controlled with a Sequential Control and Data Acquisition (SCADA) system. Using programmable logic controllers, a cost-effective SCADA system was designed …

Simtm Turing Machine Simulator, Yin Fu Chen

Theses Digitization Project

No abstract provided.

Visage: Improving The Ballistic Vulnerability Modeling And Analysis Process, Brett F. Grimes

Theses and Dissertations

The purpose of this thesis was to improve the process of modeling and analyzing ballistic vulnerability data. This was accomplished by addressing two of the more urgent needs of vulnerability analysts; the ability to display fault tree data and to edit target descriptions. A vulnerability data visualization program called VISAGE was modified to meet these needs. VISAGE was originally created to preview static shotline plots and subsequently grew into a full-featured visualization package for vulnerability target descriptions and analyses data. The next logical step in the programs evolution was to include the needed editing and fault tree display capabilities. The …

Analysis And Extension Of Model-Based Software Executives, Keith E. Lewis

Theses and Dissertations

This research developed a comprehensive description of the simulation environment of Architect, a domain-oriented application composition system being developed at the Air Force Institute of Technology to explore new software engineering technologies. The description combines information from several previous research efforts and Architect's source code into a single, comprehensive document. A critical evaluation of the simulation environment was also performed, identifying improvements and modifications that enhance Architecture's application execution capabilities by reducing complexity and execution time. The analysis was then taken one step further and presented extensions to the current simulation environment. The extensions included investigating the feasibility of mixed-mode …

A General Method For The Inverse Kinematics Of Rotational Displacements In Spatial Mechanisms, John D. Kliminski

Theses

An iterative technique was developed to solve the inverse kinematics problem for the joint rotations in both closed-loop and open-loop spatial mechanisms and robotic manipulators in any prescribed configuration. The method is based on fixing one link in space and maneuvering the other links to form a closed chain, following an approximation of the actual physical assembly of the mechanism. In order to apply the same principle to both types of mechanisms, an open-loop mechanism was modeled as a closed-loop mechanism by creating a fictitious fixed link in the free space between the base and the end of the chain …