Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Computer Engineering (50)
- Physical Sciences and Mathematics (50)
- Aerospace Engineering (45)
- Physics (27)
- Computer Engineering (20)
-
- Materials Science and Engineering (18)
- Electromagnetics and Photonics (16)
- Navigation, Guidance, Control and Dynamics (15)
- Operations Research, Systems Engineering and Industrial Engineering (14)
- Computer Sciences (12)
- Signal Processing (12)
- Aviation (11)
- Digital Communications and Networking (11)
- Engineering Science and Materials (9)
- Fluid Dynamics (9)
- Mechanical Engineering (8)
- Nuclear Engineering (8)
- Aerodynamics and Fluid Mechanics (7)
- Civil and Environmental Engineering (7)
- Information Security (7)
- Optics (7)
- Space Vehicles (7)
- Systems and Communications (7)
- Controls and Control Theory (6)
- Management and Operations (6)
- Aeronautical Vehicles (5)
- Computer and Systems Architecture (5)
- Environmental Sciences (5)
- Nanoscience and Nanotechnology (5)
- Keyword
-
- Center_CCR (14)
- Computational Fluid Dynamics (8)
- #antcenter (5)
- Cybersecurity (4)
- Optimization (4)
-
- UAV (4)
- Additive Manufacturing (3)
- Additive manufacturing (3)
- Blockchain (3)
- Boundary Layer (3)
- Fluid Dynamics (3)
- Renewable energy (3)
- Algorithms (2)
- Autonomous systems (2)
- Ceramic Matrix Composites (2)
- Chemiluminescence (2)
- Coherence (2)
- Collision Avoidance Systems (2)
- Combustion (2)
- Composite Materials (2)
- Creep Tests (2)
- Drag (2)
- Electric Propulsion (2)
- Electro-optical (2)
- Energy resilience (2)
- Failure Mode and Effect Analysis (2)
- Geolocation (2)
- Heat Transfer (2)
- Infrared (2)
- Jet Engines (2)
- Publication
- Publication Type
Articles 1 - 30 of 166
Full-Text Articles in Engineering
Tracked Vehicle Physics-Based Energy Modelling And Series Hybrid System Optimisation For The Bradley Fighting Vehicle, Travis E. Mcwhirter, Torrey J. Wagner, John E. Stubbs, Denise M. Rizzo, Jada B. Williams
Tracked Vehicle Physics-Based Energy Modelling And Series Hybrid System Optimisation For The Bradley Fighting Vehicle, Travis E. Mcwhirter, Torrey J. Wagner, John E. Stubbs, Denise M. Rizzo, Jada B. Williams
Faculty Publications
A hybrid electric tracked ground vehicle (HETGV) can reduce military fuel usage, however a review of current tools determined they are not suitable to estimate HEGTV performance. Based on topographic data and vehicle attributes, this research developed an estimation tool by creating a model to determine tracked vehicle energy and fuel requirements, and using these requirements, created a HEGTV cost and performance optimisation for the Bradley fighting vehicle energy system. The optimised design reduced fuel consumption by 15%, and met the vehicle's peak power requirement of 365 kW, with a recommended configuration of a 135 kW generator and 100 kWh …
Characterization Of Simulated Low Earth Orbit Space Environment Effects On Acid-Spun Carbon Nanotube Yarns, Ryan A. Kemnitz, Gregory R. Cobb, Abhendra K. Singh, Carl R. Hartsfield
Characterization Of Simulated Low Earth Orbit Space Environment Effects On Acid-Spun Carbon Nanotube Yarns, Ryan A. Kemnitz, Gregory R. Cobb, Abhendra K. Singh, Carl R. Hartsfield
Faculty Publications
The purpose of this study is to quantify the detrimental effects of atomic oxygen and ultraviolet (UV) C radiation on the mechanical properties, electrical conductivity, and piezoresistive effect of acid-spun carbon nanotube (CNT) yarns. Monotonic tensile tests with in-situ electrical resistance measurements were performed on pristine and exposed yarns to determine the effects of the atomic oxygen and UVC exposures on the yarn’s material properties. Both type of exposures were performed under vacuum to simulate space environment conditions. The CNT yarns’ mechanical properties did not change significantly after being exposed to UV radiation, but were significantly degraded by the atomic …
Monte Carlo And Experimental Analysis Of A Novel Directional Rotating Scatter Mask Gamma Detection System, Julie V. Logan, Darren E. Holland, Larry W. Burggraf, Justin A. Clinton, Buckley E. O'Day Iii
Monte Carlo And Experimental Analysis Of A Novel Directional Rotating Scatter Mask Gamma Detection System, Julie V. Logan, Darren E. Holland, Larry W. Burggraf, Justin A. Clinton, Buckley E. O'Day Iii
Faculty Publications
Excerpt: This work demonstrates successful experimental operation of a prototype system to identify source direction which was modeled using a library of signals simulated using GEANT and a novel algorithm....
Effect Of Surface Roughness On Ultrasonic Inspection Of Electron Beam Melting Ti‐6al‐4v, Evan T. Hanks, Anthony N. Palazotto, David Liu
Effect Of Surface Roughness On Ultrasonic Inspection Of Electron Beam Melting Ti‐6al‐4v, Evan T. Hanks, Anthony N. Palazotto, David Liu
Faculty Publications
Experimental research was conducted on the effects of surface roughness on ultrasonic non-destructive testing of electron beam melted (EBM) additively manufactured Ti-6Al-4V. Additive manufacturing (AM) is a developing technology with many potential benefits, but certain challenges posed by its use require further research before AM parts are viable for widespread use in the aviation industry. Possible applications of this new technology include aircraft battle damage repair (ABDR), small batch manufacturing to fill supply gaps and replacement for obsolete parts. This paper aims to assess the effectiveness of ultrasonic inspection in detecting manufactured flaws in EBM-manufactured Ti-6Al-4V. Additively manufactured EBM products …
Generating Electromagnetic Nonuniformly Correlated Beams, Milo W. Hyde Iv, Xifeng Xiao, David G. Voelz
Generating Electromagnetic Nonuniformly Correlated Beams, Milo W. Hyde Iv, Xifeng Xiao, David G. Voelz
Faculty Publications
We develop a method to generate electromagnetic nonuniformly correlated (ENUC) sources from vector Gaussian Schell-model (GSM) beams. Having spatially varying correlation properties, ENUC sources are more difficult to synthesize than their Schell-model counterparts (which can be generated by filtering circular complex Gaussian random numbers) and, in past work, have only been realized using Cholesky decomposition—a computationally intensive procedure. Here we transform electromagnetic GSM field instances directly into ENUC instances, thereby avoiding computing Cholesky factors resulting in significant savings in time and computing resources. We validate our method by generating (via simulation) an ENUC beam with desired parameters. We find the …
An Agent Based Model Of Passenger Boarding For Examining Commercial Aircraft Boarding Strategies, Frank W. Ciarallo, Raymond R. Hill, Kerry K. Ward
An Agent Based Model Of Passenger Boarding For Examining Commercial Aircraft Boarding Strategies, Frank W. Ciarallo, Raymond R. Hill, Kerry K. Ward
Faculty Publications
We use an agent-based simulation methodology to study airline passenger boarding using measures that reflect both the customer experience and airline efficiency perspective. This approach supports exploration of models of actual aircraft used in practice and detailed modeling of passenger dynamics. This paper discusses the modeling approach and a set of experiments comparing several boarding strategies from practical settings as well as the literature.
Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan
Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan
Theses and Dissertations
Improving and defending our nation's critical infrastructure has been a challenge for quite some time. A malfunctioning or stoppage of any one of these systems could result in hazardous conditions on its supporting populace leading to widespread damage, injury, and even death. The protection of such systems has been mandated by the Office of the President of the United States of America in Presidential Policy Directive Order 21. Current research now focuses on securing and improving the management and efficiency of Industrial Control Systems (ICS). IIoT promises a solution in enhancement of efficiency in ICS. However, the presence of IIoT …
E700xd Portable Doppler Radar Energy Systems Analysis, Brandon M. Bailey [*], Torrey J. Wagner, Jada Williams
E700xd Portable Doppler Radar Energy Systems Analysis, Brandon M. Bailey [*], Torrey J. Wagner, Jada Williams
Faculty Publications
Occurring in industrialized nations, inexpensive and abundantly available power is routinely taken for granted. However, energy resilience and to a lesser extent price are key concerns when considering potential solutions for disaster response, disaster relief, or military operations. The Department of Defense (DoD) currently uses a 5 kW generator to power the E700XD portable Doppler radar system when grid power is unavailable [1]. While the radar has an approximate power consumption of 2.5 kW, there is a potential for higher demand due to weather conditions [2]. This paper examines the cost of operating a currently installed generator, compared to the …
Deep Donors And Acceptors In Β-Ga2O3 Crystals: Determination Of The Fe2+/3+ Level By A Noncontact Method, Christopher A. Lenyk, Trevor A . Gustafson, Larry E. Halliburton, Nancy C. Giles
Deep Donors And Acceptors In Β-Ga2O3 Crystals: Determination Of The Fe2+/3+ Level By A Noncontact Method, Christopher A. Lenyk, Trevor A . Gustafson, Larry E. Halliburton, Nancy C. Giles
Faculty Publications
Electron paramagnetic resonance (EPR), infrared absorption, and thermoluminescence (TL) are used to determine the Fe2+/3+ level in Fe-doped β-Ga2O3 crystals. With these noncontact spectroscopy methods, a value of 0.84 ± 0.05 eV below the conduction band is obtained for this level. Our results clearly establish that the E2 level observed in deep level transient spectroscopy (DLTS) experiments is due to the thermal release of electrons from Fe2+ ions. The crystals used in this investigation were grown by the Czochralski method and contained large concentrations of Fe acceptors and Ir donors, and trace amounts of Cr …
Analysis Of A Celestial Icosahedron Shaped Vacuum Lighter Than Air Vehicle, Dustin P. Graves, Kyle D. Moore, Anthony N. Palazotto
Analysis Of A Celestial Icosahedron Shaped Vacuum Lighter Than Air Vehicle, Dustin P. Graves, Kyle D. Moore, Anthony N. Palazotto
Faculty Publications
Excerpt: The celestial icosahedron geometry is considered as a potential design for a vacuum lighter than air vehicle. The goal of this research is ultimately to determine the feasibility of the design and to understand the initial fluid-structure interaction of the vacuum lighter than air vehicle and the surrounding airflow.
Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake
Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake
Theses and Dissertations
Due to the infrequent and competitive nature of combat, several challenges present themselves when developing a predictive simulation. First, there is limited data with which to validate such analysis tools. Secondly, there are many aspects of combat modeling that are highly uncertain and not knowable. This research develops a comprehensive set of techniques for the treatment of uncertainty and error in combat modeling and simulation analysis. First, Evidence Theory is demonstrated as a framework for representing epistemic uncertainty in combat modeling output. Next, a novel method for sensitivity analysis of uncertainty in Evidence Theory is developed. This sensitivity analysis method …
Gamma-Ray Radiation Effects In Graphene-Based Transistors With H-Bn Nanometer Film Substrates, E. J. Cazalas, Michael R. Hogsed, S. R. Vangala, Michael R. Snure, John W. Mcclory
Gamma-Ray Radiation Effects In Graphene-Based Transistors With H-Bn Nanometer Film Substrates, E. J. Cazalas, Michael R. Hogsed, S. R. Vangala, Michael R. Snure, John W. Mcclory
Faculty Publications
Radiation effects on graphene field effect transistors (GFETs) with hexagonal boron nitride (h-BN) thin film substrates are investigated using 60Co gamma-ray radiation. This study examines the radiation response using many samples with varying h-BN film thicknesses (1.6 and 20 nm thickness) and graphene channel lengths (5 and 10 μm). These samples were exposed to a total ionizing dose of approximately 1 Mrad(Si). I-V measurements were taken at fixed time intervals between irradiations and postirradiation. Dirac point voltage and current are extracted from the I-V measurements, as well as mobility, Dirac voltage hysteresis, and the total number of GFETs that remain …
Mitigation Of Anisotropic Fatigue In Nickel Alloy 718 Manufactured Via Selective Laser Melting, Volodymyr P. Sabelkin, Gregory R. Cobb, Travis E. Shelton, Megan N. Hartsfield, David J. Newell, Ryan P. O'Hara, Ryan A. Kemnitz
Mitigation Of Anisotropic Fatigue In Nickel Alloy 718 Manufactured Via Selective Laser Melting, Volodymyr P. Sabelkin, Gregory R. Cobb, Travis E. Shelton, Megan N. Hartsfield, David J. Newell, Ryan P. O'Hara, Ryan A. Kemnitz
Faculty Publications
The tension-tension fatigue behavior of heat treated selective laser melted (SLM) nickel alloy 718 (IN718) tensile specimens was tested and compared to as-built specimens. In addition to the industry standard IN718 heat treatment, a modified heat treatment was developed and tested in order to mitigate the anisotropic mechanical properties inherent to SLM materials. Electron backscatter diffraction verified that the modified heat treatment significantly affected the microstructure in all build planes. Three different print orientations were studied to determine their effect on the fatigue behavior. Both heat treatments improved the fatigue life of the specimens, although neither surpassed the fatigue life …
Measurement Of Electron Density And Temperature From Laser-Induced Nitrogen Plasma At Elevated Pressure (1–6 Bar), Ashwin P. Rao [*], Mark Gragston, Anil K. Patnaik, Paul S. Hsu, Michael B. Shattan
Measurement Of Electron Density And Temperature From Laser-Induced Nitrogen Plasma At Elevated Pressure (1–6 Bar), Ashwin P. Rao [*], Mark Gragston, Anil K. Patnaik, Paul S. Hsu, Michael B. Shattan
Faculty Publications
Laser-induced plasmas experience Stark broadening and shifts of spectral lines carrying spectral signatures of plasma properties. In this paper, we report time-resolved Stark broadening measurements of a nitrogen triplet emission line at 1–6 bar ambient pressure in a pure nitrogen cell. Electron densities are calculated using the Stark broadening for different pressure conditions, which are shown to linearly increase with pressure. Additionally, using a Boltzmann fit for the triplet, the electron temperature is calculated and shown to decrease with increasing pressure. The rate of plasma cooling is observed to increase with pressure. The reported Stark broadening based plasma diagnostics in …
Multiple Pursuer Multiple Evader Differential Games, Eloy Garcia, David Casbeer, Alexander Von Moll, Meir Pachter
Multiple Pursuer Multiple Evader Differential Games, Eloy Garcia, David Casbeer, Alexander Von Moll, Meir Pachter
Faculty Publications
In this paper an N-pursuer vs. M-evader team conflict is studied. The differential game of border defense is addressed and we focus on the game of degree in the region of the state space where the pursuers are able to win. This work extends classical differential game theory to simultaneously address weapon assignments and multi-player pursuit-evasion scenarios. Saddle-point strategies that provide guaranteed performance for each team regardless of the actual strategies implemented by the opponent are devised. The players' optimal strategies require the co-design of cooperative optimal assignments and optimal guidance laws. A representative measure of performance is proposed and …
Adaptive-Hybrid Redundancy With Error Injection, Nicholas S. Hamilton, Scott R. Graham, Timothy Carbino, James C. Petrosky, J. Addison Betances
Adaptive-Hybrid Redundancy With Error Injection, Nicholas S. Hamilton, Scott R. Graham, Timothy Carbino, James C. Petrosky, J. Addison Betances
Faculty Publications
Adaptive-Hybrid Redundancy (AHR) shows promise as a method to allow flexibility when selecting between processing speed and energy efficiency while maintaining a level of error mitigation in space radiation environments. Whereas previous work demonstrated AHR’s feasibility in an error free environment, this work analyzes AHR performance in the presence of errors. Errors are deliberately injected into AHR at specific times in the processing chain to demonstrate best and worst case performance impacts. This analysis demonstrates that AHR provides flexibility in processing speed and energy efficiency in the presence of errors
The Challenges Of Low-Energy Secondary Electron Emission Measurement, Matthew J. Vincie
The Challenges Of Low-Energy Secondary Electron Emission Measurement, Matthew J. Vincie
Theses and Dissertations
The phenomena known as secondary electron emission was discovered over a century ago. Yet it remains very difficult to model accurately due to the limited availability of reliable experimental data. With the growing use of computer simulations in hardware development, the need for accurate models has increased. This research focused on determining what factors may be causing measurement discrepancies and methods for increasing the accuracy of measurements. It was found that several assumptions are commonly invoked when these measurements are performed that may not always be consistent with reality. The violation of these assumptions leads to measurement bias that is …
Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins
Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins
Theses and Dissertations
As space becomes an increasingly congested domain, the risk of damage to satellite constellations is increasing. In response, there is an increasing need for capabilities for unmanned repair, refueling, and reconstitution (R3) of those constellations. Cislunar orbits offer a promising storage and low-cost transfer solution for on-orbit service vehicles and replacement satellites to leverage those capabilities. This research makes use of mixed-integer linear programming-based logistics models to determine the situations in which a cislunar mission architecture would offer a cost-effective alternative to Earth-based R3. The network models presented in this research make use of the latest developments in Event-Driven Generalized …
Thermal Management Using Microelectromechanical Systems Bimorph Cantilever Beams, Ronald A. Coutu Jr., Robert S. Lafleur, John P. K. Walton, Laverne A. Starman
Thermal Management Using Microelectromechanical Systems Bimorph Cantilever Beams, Ronald A. Coutu Jr., Robert S. Lafleur, John P. K. Walton, Laverne A. Starman
AFIT Patents
A cooling structure for a heat source, where the cooling structure includes a beam having a first end and a second end and a length disposed therebetween. The beam is formed at least in part of a first material having a first thermal coefficient of expansion and a second material having a second thermal coefficient of expansion, where the first thermal coefficient of expansion is different from the second thermal coefficient of expansion. The first end of the beam is thermally connected to the heat source, such that heat generated by the heat source is conducted along the length of …
Quantifying The Effects Of Hyperthermal Atomic Oxygen And Thermal Fatigue Environments On Carbon Nanotube Sheets For Space-Based Applications, Jacob W. Singleton, Gregory R. Cobb, Heath E. Misak, Ryan A. Kemnitz
Quantifying The Effects Of Hyperthermal Atomic Oxygen And Thermal Fatigue Environments On Carbon Nanotube Sheets For Space-Based Applications, Jacob W. Singleton, Gregory R. Cobb, Heath E. Misak, Ryan A. Kemnitz
Faculty Publications
The effects of atomic oxygen and thermal fatigue on two different types of carbon nanotube sheets were studied. One set was treated with nitric acid, while the other set was left untreated. Monotonic tensile tests were performed before and after exposure to determine the effects of either exposure type on the sheets’ mechanical properties. Electrical conductivity and electromagnetic interference measurements were recorded to determine the effects of AO-exposure and thermal cycling on the sheets’ electrical properties. Neither exposure type affected the sheets’ specific strengths. Both exposure types increased the sheets’ specific stiffnesses and decreased the sheets’ strains at failure. The …
Insulation Sensitivity Analysis For An Optimized Fabric Shelter Off-Grid Hybrid Energy System, Jay F. Pearson [*], Torrey J. Wagner, Steven Schuldt
Insulation Sensitivity Analysis For An Optimized Fabric Shelter Off-Grid Hybrid Energy System, Jay F. Pearson [*], Torrey J. Wagner, Steven Schuldt
Faculty Publications
During military and disaster relief operations, connecting to an established electrical grid is rarely an option. In these situations, camps consisting of poorly insulated fabric shelters are predominantly powered by inefficient diesel generators that require frequent fuel resupply. In order to reduce the fuel demand of these generators, camps may utilize photovoltaic-battery systems. This paper presents an innovative cost-performance model capable of optimizing solar array size, battery backup system, and shelter insulation type to minimize the operating cost of powering a single fabric shelter. Model performance was evaluated using one year of insolation, weather and energy requirement data from a …
Nonlinearities And Carrier Dynamics In Refractory Plasmonic Tin Thin Films, Heather George, Jennifer Reed, Manuel R. Ferdinandus, Clayton Devault, Alexei Lagutchev, Augustine Urbas, Theodore B. Norris, Vladimir M. Shalaev, Alexandra Boltasseva, Nathaniel Kinsey
Nonlinearities And Carrier Dynamics In Refractory Plasmonic Tin Thin Films, Heather George, Jennifer Reed, Manuel R. Ferdinandus, Clayton Devault, Alexei Lagutchev, Augustine Urbas, Theodore B. Norris, Vladimir M. Shalaev, Alexandra Boltasseva, Nathaniel Kinsey
Faculty Publications
Titanium nitride is widely used in plasmonic applications, due to its robustness and optical properties which resemble those of gold. Despite this interest, the nonlinear properties have only recently begun to be investigated. In this work, beam deflection and non-degenerate femtosecond pump-probe spectroscopy (800 nm pump and 650 nm probe) were used to measure the real and imaginary transient nonlinear response of 30-nm-thick TiN films on sapphire and fused silica in the metallic region governed by Fermi-smearing nonlinearities. In contrast to other metals, it is found that TiN exhibits non-instantaneous positive refraction and reverse saturable absorption whose relaxation is dominated …
Possible Detection Of Low Energy Solar Neutrons Using Boron Based Materials, Nicole Benker, Elena Echeverria, Robert Olesen, Brant E. Kananen, John W. Mcclory, Yaroslav V. Burak, Volodymyr T. Adamiv, Ihor M. Teslyuk, George Glenn Peterson, Ben Bradley, Ethiyal R. Wilson, James C. Petrosky, Bin Dong, Jeffry Kelber, Jennifer Hamblin, Jaques Doumani, Peter A. Dowben, Alex Enders
Possible Detection Of Low Energy Solar Neutrons Using Boron Based Materials, Nicole Benker, Elena Echeverria, Robert Olesen, Brant E. Kananen, John W. Mcclory, Yaroslav V. Burak, Volodymyr T. Adamiv, Ihor M. Teslyuk, George Glenn Peterson, Ben Bradley, Ethiyal R. Wilson, James C. Petrosky, Bin Dong, Jeffry Kelber, Jennifer Hamblin, Jaques Doumani, Peter A. Dowben, Alex Enders
Faculty Publications
Solar neutrons have been detected aboard the International Space Station (ISS), using lithium tetraborate and boron carbide detector elements. We find that evidence of a solar neutron flux, as detected in a neutron calorimeter following subtraction of the proton background, with an energy of about 2 to 4 MeV. This solar neutron flux is likely no more than 250 to 375 neutrons cm−2sec−1, with a lower bound of 50–75 neutrons cm−2sec−1 at one au.
Nonlinear Characterizing Of A New Titanium Nitride On Aluminum Oxide Metalens, Michael A. Cumming
Nonlinear Characterizing Of A New Titanium Nitride On Aluminum Oxide Metalens, Michael A. Cumming
Theses and Dissertations
A sample metalens generated from Titanium Nitride deposited onto Aluminum Oxide was designed to focus at 10 microns with a beam centered at 800nm, and when analyzed with high intensity illumination was found to have a focal length of 9.650 ±.003µm at an intensity of 16.93[MW/cm2 ]. Analyzing this change by comparing it to a Fresnel Lens’ physics shows that for this lens, the effective nonlinear index of refraction is certainly greater than the nonlinear index of just Titanium Nitride itself, at −1.6239 × 10−15[m2/W] compared to the materials −1.3 × 10−15[m2 …
Adaptive-Hybrid Redundancy For Radiation Hardening, Nicolas S. Hamilton
Adaptive-Hybrid Redundancy For Radiation Hardening, Nicolas S. Hamilton
Theses and Dissertations
An Adaptive-Hybrid Redundancy (AHR) mitigation strategy is proposed to mitigate the effects of Single Event Upset (SEU) and Single Event Transient (SET) radiation effects. AHR is adaptive because it switches between Triple Modular Redundancy (TMR) and Temporal Software Redundancy (TSR). AHR is hybrid because it uses hardware and software redundancy. AHR is demonstrated to run faster than TSR and use less energy than TMR. Furthermore, AHR allows space vehicle designers, mission planners, and operators the flexibility to determine how much time is spent in TMR and TSR. TMR mode provides faster processing at the expense of greater energy usage. TSR …
Target Detection In Heterogeneous Clutter With Low Resolution Radar, Kyle G. Stankowski
Target Detection In Heterogeneous Clutter With Low Resolution Radar, Kyle G. Stankowski
Theses and Dissertations
This thesis develops a framework for SAR target detection and super-resolution in low-resolution environments. The primary focus in this research is the background clutter heterogeneity that often accompanies low range and cross-range resolutions. A corrective model which accounts for clutter replacement is developed to define the detection and false alarm rates of the detector more accurately than a traditional model in which the radar return from the target supplements the existing clutter. In a heterogeneous clutter cell, the clutter replacement model leverages the different scattering distributions among the individual clutter types to generate a probability distribution function for the areas …
Enabling Mobile Neutron Detection Systems With Clyc, Matthew C. Recker
Enabling Mobile Neutron Detection Systems With Clyc, Matthew C. Recker
Theses and Dissertations
Cs2LiYCl6:Ce3+ (CLYC) has the desirable property of being sensitive to both gamma rays and neutrons while producing waveforms suitable for pulse shape discrimination (PSD) to determine which radiation was detected. This dissertation examines the behavior of CLYC to support its further development for mobile and portable applications. First, the feasibility of performing PSD with CLYC and an inexpensive data acquisition system was examined. This system was able to clearly distinguish both events with a figure of merit of 1.42. Next, the performance of a SiPM was compared to a traditional PMT. Analysis showed that the …
Peptide Nanotube Encapsulated Enzyme Biosensor For Vapor Phase Detection Of Malathion, An Organophosphorus Compound, Christopher W. Edwards, Surachet Duanghathaipornsuk, Mark N. Goltz, Sushil Kanel, Dong-Shik Kim
Peptide Nanotube Encapsulated Enzyme Biosensor For Vapor Phase Detection Of Malathion, An Organophosphorus Compound, Christopher W. Edwards, Surachet Duanghathaipornsuk, Mark N. Goltz, Sushil Kanel, Dong-Shik Kim
Faculty Publications
This study explores the use of a butyrylcholinesterase (BChE)-based, reversible reaction biosensor using screen-printed electrodes (SPEs) having a smaller working surface area than the single-use electrodes previously studied. Previous research demonstrated the prospective application of a single-use biosensor fabricated with an acetylcholinesterase (AChE) enzyme encapsulated in peptide nanotubes (PNTs) and enhanced with horseradish peroxidase (HRP) to detect organophosphorus compounds (OPCs) in aqueous and gas phases. In the current study, potential improvements to the biosensor are investigated. BChE-based biosensors were fabricated using PNTs, HRP, and Nafion in combination to increase the reactive surface area, enhance sensitivity, and maintain enzyme stability. Cyclic …
A Study Of Onboarding And Turnover Mediating Variables In U.S. Air Force Officers, Brett S. Bowers
A Study Of Onboarding And Turnover Mediating Variables In U.S. Air Force Officers, Brett S. Bowers
Theses and Dissertations
Employee retention, while always a concern in the workplace, has become a greater challenge for organizations in recent years. Today’s working class has displayed a propensity to change jobs more rapidly than previous generations, exacerbating not only turnover rates but also the costs associated with them (Frankel, 2016). This challenge is especially relevant to the United States Air Force, which has experienced difficulty retaining young officers in recent years. The problems resulting from this voluntary turnover are exceedingly impactful to the military command structure, as senior leaders must work their way up from the lowest ranks. As such, the Air …
Quantitative Analysis Of Cerium-Gallium Alloys Using A Hand-Held Laser Induced Breakdown Spectroscopy Device, Ashwin P. Rao, Matthew Cook, Howard L. Hall, Michael B. Shattan
Quantitative Analysis Of Cerium-Gallium Alloys Using A Hand-Held Laser Induced Breakdown Spectroscopy Device, Ashwin P. Rao, Matthew Cook, Howard L. Hall, Michael B. Shattan
Faculty Publications
A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from laser-induced plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging from 0–3 weight percent. Ionic and neutral emission lines of the two constituent elements were then extracted and used to generate calibration curves relating the emission line intensity ratios to the gallium concentration of the alloy. The Ga I 287.4-nm emission line was determined to be superior for the purposes of Ga detection and concentration determination. A limit of detection below 0.25%was achieved using a multivariate regression model of the Ga I …