Engineering Commons^™

Optical Characterization Of Wide Bandgap Detector-Grade Semiconductors, Ezzat Elshazly

Theses and Dissertations

Wide bandgap semiconductors are being widely investigated because they have the potential to satisfy the stringent material requirements of high resolution, room temperature gamma-ray spectrometers. In particular, Cadmium Zinc Telluride (Cd1-xZnxTe, x~0.1) and Thallium Bromide (TlBr), due to their combination of high resistivity, high atomic number and good electron mobility, have became very promising candidates for use in X- and gamma-ray detectors operating at room temperature. In this study, carrier trapping times were measured in CZT and TlBr as a function of temperature and material quality. Carrier lifetimes and tellurium inclusion densities were measured in detector-grade Cadmium Zinc Telluride (CZT) …

A Computationally-Assisted Methodology For Rapid Exploration Of Design Possibilities In Conceptual Design, Garrett J. Barnum

Theses and Dissertations

One of the most important decisions in the product development process is the selection of a promising design concept because of the large influence it has on the final product. A thorough search for the best design is a significant challenge to designers, who are trying to balance the objective and subjective performance of the designs they create. In this thesis, a computationally-assisted design methodology is developed and used in the early stages of design to more thoroughly search for designs that perform well according to objective physics-based models and subjective designer-specific preference-based models. The method presented herein uses an …

Effect Of Relative Density And Stress Level On The Bearing Capacity Of Footings On Sand, D Loukidis, Rodrigo Salgado

Lyles School of Civil Engineering Faculty Publications

The design of shallow foundations relies on bearing capacity values calculated using empirical procedures that are based in part on solutions obtained using the method of characteristics, which assumes a soil that is perfectly plastic following an associated flow rule. In this paper the problem of strip and circular footings resting on the surface of a sand layer is analysed using the finite-element method. Analyses are performed using a two-surface plasticity constitutive model that realistically captures the aspects of the mechanical response of sands that are relevant to the bearing capacity problem. In particular, the model accounts for non-associated flow, …

Concurrently Evolving Sensor Morphology And Control For A Hexapod Robot, Gary Parker, Pramod J. Nathan

Computer Science Faculty Publications

Evolving a robot’s sensor morphology along with its control program has the potential to significantly improve its effectiveness in completing the assigned task, plus accommodates the possibility of allowing it to adapt to significant changes in the environment. In previous work, we presented a learning system where the angle, range, and type of sensors on a hexapod robot, along with the control program, were evolved. The evolution was done in simulation and the tests, which were also done in simulation, showed that effective sensor morphologies and control programs could be co-learned by the system. In this paper, we describe the …

Using Evolutionary Strategies For The Real-Time Learning Of Controllers For Autonomous Agents In Xpilot-Ai, Gary Parker, Michael H. Probst

Computer Science Faculty Publications

Real-time learning is the process of an artificial intelligence agent learning behavior(s) at the same pace as it operates in the real world. Video games tend to be an excellent locale for testing real-time learning agents, as the action happens at real speeds with a good visual feedback mechanism, coupled with the possibility of comparing human performance to that of the agent's. In addition, players want to be competing against a consistently challenging opponent. This paper is a discussion of a controller for an agent in the space combat game Xpilot and the evolution of said controller using two different …

Tribological Comparison Of Traditional And Advanced Firearm Coatings, Greg Boban

Master's Theses

The objective of this project is to find which type of coating has the best performance characteristics for finishing firearms. This is accomplished by measuring and comparing several performance characteristics, such as: adhesion, hardness, wear resistance, friction control, and corrosion resistance. Appearance is not a factor since any exterior coating that is flashy can be subdued or camouflaged with special purpose paints, which have proven durable enough for such purposes. Cost will not be a limiting factor for this experiment, but will be discussed in the conclusion as a secondary concern. This data will be used to identify the best …

Acuta Enews July 2010, Vol 39, No. 7

ACUTA Newsletters

ln This lssue

From ACUTA Headquarters: FCC: Traveling with Wireless Phones .....Jeri A. Semer, CAE, Executive Dir.

Why Should You Visit the ACUTA Community Often?

Tech Talk: The lnternet Just Keeps on Growing ....Kevin Tanzillo, Dux PR

Hurricane Preparedness Checklist

Cloud Security, Some Guidance...........Gary Audin, Delphi, lnc.

lnfo Links ............. Randy Hayes, Univ. of Northern lowa

Write for the ACUTA Journal in 2011

Second-Notice Membership Dues Mailed July 1

Washington Update Newsletter

Board Report......... George Denbow, Univ. of Texas, Austin

New Members

Check lt Out: Press Releases...Job Postings...RFls/RFPs...Special Deals

Discussion Of "Potential Dangers Of Simplifying Combined Sewer Hydrologic/Hydraulic Models” By Joshua P. Cantone And Arthur R. Schmidt, Arturo S. León, Leonardo S. Nania, Venkataramana Sridhar

Civil Engineering Faculty Publications and Presentations

The authors of this paper provide a valuable discussion on the potential dangers of conduit skeletonization and subcatchment aggregation. For assessing these potential dangers, a "base model" (includes all sewers, nodes, inlets and gutters) and simplified models (successive removal of elements) of two catchments were used. The discussers congratulate the authors for their work on this relevant issue and for presenting their results in a clear and well organized way. The discussers however would like to raise some questions and comments regarding the results and their interpretation as presented in the paper.

Department Of Biological Systems Engineering Newsletter, Volume 6, Number 2, July 2010

BSE Department Magazine

No abstract provided.

Viscosity Effects In Vibratory Mobilization Of Residual Oil, Igor A. Beresnev, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The last decade has seen clarifications of the underlying capillary physics behind stimulation of oil production by seismic waves and vibrations. Computational studies have prevailed, however, and no viscous hydrodynamic theory of the phenomenon has been proposed. For a body of oil entrapped in a pore channel, viscosity effects are naturally incorporated through a model of two-phase core-annular flow. These effects are significant at the postmobilization stage, when the resistance of capillary forces is overcome and viscosity becomes the only force resisting an oil ganglion's motion. A viscous equation of motion follows, and computational fluid dynamics (CFD) establishes the limits …

2,4,6-Tri­Phenyl­Aniline, Onome Ugono, Stephanie Cowin, Alicia M. Beatty

Educator Preparation & Leadership Faculty Works

No abstract provided.

Assessment Of Climatic Vulnerability In The Upper Thames River Basin: Part 2, Leanna King, Tarana A. Solaiman, Slobodan P. Simonovic

Water Resources Research Report

Increasing greenhouse gas emissions will cause global temperature to rise in the coming years. Understanding the effects of rising temperature on the hydrologic cycle at a local scale is important in order to assess a wide scope of climate change impacts on management of water resources. Coupled Atmosphere-Ocean General Circulation Models (AOGCMs) are state-of-theart in climate change research, predicting the future climate based on plausible emission scenarios. Their spatial and temporal scales are quite large, so the results of their analyses must be brought to a local-scale through a downscaling process. There are several methods for downscaling AOGCM data; however …

A Single Chip Computational Sensor System For Neutron Detection Applications, Nathan R. Schemm, Sina Balkir, Michael Hoffman, Mark Bauer, David Schultz, James C. Petrosky, John W. Mcclory, Marcus Natta, Jennifer I. Brand, Jinke Tang, Wendong Wang

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents the design and test results of a standalone computational radiation sensor system based on a single chip solution. A low-power sensor front end with a charge sensitive amplifier and an event driven analog-to-digital converter is integrated on the same chip as a dedicated microcontroller to process and bin the data from the neutron detector diode heterojunction according to pulse height. This combination effectively implements a single chip multichannel analyzer with the capability to do further processing of the data in software. The design was fabricated in a 0.18 CMOS technology with field tests demonstrating the validity of …

Modeling And Its Numerical Method For Micro-Scaled Diffusion -Reaction Systems In The Neuromuscular Junction, Abdul Khaliq

Doctoral Dissertations

The main subject of this research is the neuromuscular junction (NMJ). The NMJ is a biological structure composed of the interface between a neuron and a muscle cell. Currently, there is not a fully three dimensional model of diffusion-reaction processes occurring in the NMJ. Developing a useful predictive model of this structure will assist in the therapeutic efforts to restore and rehabilitate NMJ function to humans and in developing strategies to prevent damage to the NMJ. This research work developed 1D mass transport and full 3D reaction diffusion models. A new finite difference scheme is presented for solving 1D mass …

From Computing Sets Of Optima, Pareto Sets, And Sets Of Nash Equilibria To General Decision-Related Set Computations, Vladik Kreinovich

Departmental Technical Reports (CS)

Several algorithms have been proposed to compute sets of optima, Pareto sets, sets of Nash equilibria. In this paper, we present a general algorithm for decision-related set computations that includes all these algorithms as particular cases.

To make our algorithm understandable to people working in optimization and in game theory, we also provide motivations and explanations for our formalizations of the corresponding problems and for the related notions of computable mathematics.

In Vivo Non-Invasive Monitoring Of Optically Resonant Metal Nanoparticles Using Multi-Wavelength Photoplethysmography, Gregory J. Michalak

Doctoral Dissertations

Nanotechnology has recently emerged as a powerful modality in many biomedical applications. In particular, several classes of nanoparticles have been employed as cancer therapy and imaging contrast agents. These particles can have architecture of varying complexity, depending on their specific application. These complex architectures are achieved by various chemical techniques usually performed in specific sequences to add complexity and functionality. One such class of nanoparticle, used in tumor treatment and as contrast agents in several optical imaging techniques, is the plasmon resonant metal nanoparticle. The most common metal used for these particles is gold because of its biocompatibility, lack of …

Elimination Of Deck Joints Using A Corrosion Resistant Frp Approach, Ashok Reddy Aleti

Doctoral Dissertations

The research presented herein describes the development of durable link slabs for jointless bridge decks based on using FRP grid for reinforcement. Specifically, the ductility of the FRP material was utilized to accommodate bridge deck deformations imposed by girder deflection, temperature variations, and concrete shrinkage. It would also provide a solution to a number of deterioration problems associated with bridge deck joints.

The design concept of the link slabs was then examined to form the basis of design for FRP grid link slabs. Improved design of FRP grid link slab/concrete deck slab interface was confirmed in the numerical analysis. The …

Recombinant Factors For Hemostasis, Jennifer Calcaterra

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Trauma deaths are a result of hemorrhage in 37% of civilians and 47% military personnel and are the primary cause of death for individuals under 44 years of age. Current techniques used to treat hemorrhage are inadequate for severe bleeding. Preliminary research indicates that fibrin sealants (FS) alone or in combination with a dressing may be more effective; however, it has not been economically feasible for widespread use because of prohibitive costs related to procuring the proteins. To meet future demands for hemostatic therapies, FS will likely include recombinant human fibrinogen (rFI) and recombinant human Factor XIII (rFXIII). The underlying …

Load Rating Of Complex Bridges, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Extension To Multiple Species Of A Two-Equation Turbulence Model For High Speed Flows, Martin Horvath

Master's Theses - Daytona Beach

The Wilcox (2006) k-co turbulence model has been extended to multiple species and implemented in a CFD code for high speed flows using the Steger-Warming flux-vector splitting scheme. The model was chosen because compressibility corrections are not required, nor are viscous damping factors or wall functions to produce the law of the wall, and it has previously been validated for approximately one hundred test cases ranging from incompressible to hypersonic flow regimes. Initial validation cases using first-order accuracy have been performed, including a Mach 2.5 flow past a backward-facing step and a Mach 2.85 flow into a 24° compression corner. …

Informatics And Natural Computation: Final Report, Francis T. Marchese

Cornerstone 3 Reports : Interdisciplinary Informatics

The purpose of this grant is to develop an interdisciplinary course in Informatics and Natural Computation that would service undergraduate computer, natural, and physical science majors. Informatics is the science of information, the practice of information processing, and the engineering of information systems. Informatics studies the structure, algorithms, behavior, and interactions of natural and artificial systems that store, process, access and communicate information. Natural computing refers to a collection of disciplines that unite nature with computing in three distinct ways:

1. Nature serves as a source of inspiration for the development of computational tools or systems that are used for …

Knudsen Force Modeling In Application To Microsystems, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

At the microscale, even moderate temperature differences can result in significant Knudsen forces generated by the energy exchange between gas molecules and solids immersed in a gas. Creating, controlling and measuring Knudsen forces in microsystems can be an arduous task since only limited theory exists at present. This present study investigates the mechanism of Knudsen forces in detail based on numerical solution of the Boltzmann kinetic equation. The Knudsen force is shown, in general, to be a result of thermal nonequilibrium between gas and solid. The simulations are validated by comparison with experimental measurements that have been reported by Passian …

What Determines Knudsen Force At The Microscale, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

Knudsen forces arise in microscale systems when there is a thermal gradient with a characteristic length scale comparable to the molecular mean free path of the ambient gas. These forces are sometimes referred as radiometric or thermo-molecular forces [1] and have been recently measured experimentally in a microscale configuration using heated atomic force microscopy (AFM) probes [2]. The Knudsen force on microstructures with thermal gradients can provide a novel actuation mechanism for mass detection, thermogravimetry, and very high-resolution heat flux measurements. While measuring such forces precisely at microscale can be an arduous task especially since only limited analytical results exist, …

High Performance Atomic-Layer-Deposited Laluo3/Ge-On-Insulator P-Channel Metal-Oxide-Semiconductor Field-Effect Transistor With Thermally Grown Geo2 As Interfacial Passivation Layer, J J. Gu, Y Q. Liu, M Xu, G K. Celler, R G. Gordon, P. D. Ye

Birck and NCN Publications

Enhancement-mode p-channel metal-oxide-semiconductor field-effect transistor (MOSFET) on germanium-on-insulator substrate is fabricated with atomic-layer-deposited (ALD) LaLuO3 as gate dielectric. Significant improvement in both on-state current and effective hole mobility has been observed for devices with thermal GeO2 passivation. The negative threshold voltage (V-T) shift in devices with GeO2 interfacial layer (IL) further demonstrates the effectiveness of surface passivation. Results from low temperature mobility characterization show that phonon scattering is the dominant scattering mechanism at a large inversion charge, indicating good interface quality. The combination of higher-k LaLuO3 and ultrathin GeO2 IL is a promising solution to the tradeoff between the aggressive …

The Taiwan Civil Aviation Safety Reporting (Tacare) System In Aircraft Maintenance: An Evaluation Of The Acceptance Of Voluntary Incident Reporting Programs For Maintenance Personnel In Taiwan, Yi-Fan (Tom) Chen

Master's Theses - Daytona Beach

The purpose of this research was to examine the effectiveness of the Taiwan Civil Aviation safety reporting (TACARE) system for maintenance personnel to improve aircraft safety. The research evaluated what are the issues that affect the participation of the TACARE system. The understandings of the safety culture for maintenance personnel in Taiwan were also analyzed. The research was conducted with a mixed method. The survey and interview were developed to sample the acceptance and opinions regarding the TACARE system for the maintenance personnel in Taiwan. Statistical analysis of the data from 605 survey respondents and 9 interviewees concluded the maintenance …

Nonlinear Observers For Human-In-The-Loop Control Systems, Samuel Kitchen Mckinley

Master's Theses - Daytona Beach

The development of models for a human-in-the-loop with hardware is an area of ongoing research. The ability to simulate a human-in-the-loop with hardware provides a platform for better understanding the dynamics of human and machine cognition. A human-in-the-loop model provides information that can be used to design more efficient human interfaces and smarter autonomous assistant controllers. This can make a complex task such as flying an aircraft safer and more accessible. This thesis explores different possibilities for human operator models to be modeled in the loop with a vehicle. A human is modeled as a linear state feedback controller in …

Redesigning Airport Diagrams With Principles Of Cognitive Psychology, Jacob Miller

Master's Theses - Daytona Beach

The aviation community strives for air travel to be the safest form of transportation. The National Transportation Safety Board published a “Most Wanted” list to acknowledge the most threatening safety issues, and runway safety and runway incursions were at the top of their list. Furthermore, runway incursion statistics by the Federal Aviation Administration show that pilot deviations were the most common cause for runways incursions. Misunderstandings of airport diagrams may be one reason for pilot deviations. While navigating through airport taxiways, pilots refer to their airport diagrams as a map of the airport. Unfortunately, airport diagrams are not designed with …

Mitigation Of Chloride And Sulfate Based Corrosion In Reinforced Concrete Via Electrokinetic Nanoparticle Treatment, Kunal Kupwade-Patil

Doctoral Dissertations

Concrete is a porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources, including sea salt spray, direct seawater wetting, deicing salts and chlorides can contaminate reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the reinforcement. When chloride concentration at the reinforcement exceeds a threshold level it breaks down the passive oxide layer, leading to chloride induced corrosion. The application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of …

Failure Literacy In Structural Engineering, Norbert J. Delatte

Civil and Environmental Engineering Faculty Publications

The history of the development of practice in many engineering disciplines is, in large part, the story of failures, both imminent and actual, and of the changes to designs, standards and procedures made as the result of timely interventions or forensic analyses. All engineers, and more particularly structural engineers, should be failure literate. Failure literacy means knowing about the critical historical failure cases that have shaped the profession: not merely the surface technical details, but the environment, the communications difficulties and the procedural issues. In the US, an intensive effort has been under way for nearly a decade to promote …

Flight Physician - July, 2010, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A sixteen page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.