Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform,
2013
California Polytechnic State University, San Luis Obispo
Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.
Master's Theses
This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …
Early Wildfire Detection Using Temporal Filtering And Multi-Band Infrared Analysis,
2013
California Polytechnic State University, San Luis Obispo
Early Wildfire Detection Using Temporal Filtering And Multi-Band Infrared Analysis, Ansel John Boynton
Master's Theses
Every year wildfires threaten or destroy ecological habitats, man-made infrastructure and people’s lives. Additionally millions of dollars are spent each year trying to prevent and control these fires. Ideally if a wildfire can be detected before it rages out of control it can be extinguished and avoid large scale devastation. Traditional manned fire lookout towers are neither cost effective nor particularly efficient at detecting wildfire. It is proposed that temporal filtering can be used to isolate the signals created at the beginnings of potential wildfires. Temporal filtering can remove any background image and any periodic signals created by the camera …
A Novel Unit Cell Antenna For Highly Integrated Phased Arrays In The Shf Band,
2013
California Polytechnic State University, San Luis Obispo
A Novel Unit Cell Antenna For Highly Integrated Phased Arrays In The Shf Band, Timothy Bryan Ogilvie
Master's Theses
Phased arrays are electromagnetic antenna systems comprised of many radiating elements and processing electronics. Radiating elements are typically positioned in an orderly grid within the antenna aperture. In the receive mode of operation, radiating elements capture some of the signal energy from incoming radiation and guide these signals to processing electronics. Signals are filtered and amplified to maintain the desired sensitivity and complexly weighted using circuits with reconfigurable amplification gain and phase delay. Finally, all signals are combined. The summation of these complexly weighted spatial samples forms a spatial filter in the same way complexly weighted temporal samples establish a …
Nanowire Metal-Insulator-Metal Plasmonic Devices,
2013
University of Dayton
Nanowire Metal-Insulator-Metal Plasmonic Devices, Joseph W. Haus, Li Li, Cong Deng, Nkorni Katte, Michael Scalora, Domenico De Ceglia, Maria Antonietta Vincenti
Electro-Optics and Photonics Faculty Publications
In this paper we theoretically study the responsivity of Metal-Insulator-Metal nanostructures to light illumination over a broad wavelength band (1 - 25 microns) and we examine the role of a local field enhancement and electrostatic field on the responsivity.
Plasmonic Nanostructures For The Absorption Enhancement Of Silicon Solar Cells,
2013
University of Arkansas, Fayetteville
Plasmonic Nanostructures For The Absorption Enhancement Of Silicon Solar Cells, Nathan Matthias Burford
Graduate Theses and Dissertations
In this work, computational investigation of plasmonic nanostructures was conducted using the commercial finite element electromagnetics solver Ansys® HFSS. Arrays of silver toroid nanoparticles located on the surface of an amorphous silicon thin-film absorbing layer were studied for particle sizes ranging from 20 nm to 200 nm in outer diameter. Parametric optimization by calculating an approximation of the photocurrent enhancement due to the nanoparticles was performed to determine optimal surface coverage of the nanoparticles. A comparison was made between these optimized nanotoroid arrays and optimized nanosphere arrays based on spectral absorption enhancement and potential photocurrent enhancement in an amorphous silicon …
Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor,
2013
Utah State University
Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Due to the current public demand of faster, more powerful, and more reliable electronic devices, research is prolific these days in the area of high electron mobility transistor (HEMT) devices. This is because of their usefulness in RF (radio frequency) and microwave power amplifier applications including microwave vacuum tubes, cellular and personal communications services, and widespread broadband access. Although electrical transistor research has been ongoing since its inception in 1947, the transistor itself continues to evolve and improve much in part because of the many driven researchers and scientists throughout the world who are pushing the limits of what modern …
Determination Of Ionospheric Current Systems By Measuring The Phase Shift On Amateur Satellite Frequencies,
2013
Utah State University
Determination Of Ionospheric Current Systems By Measuring The Phase Shift On Amateur Satellite Frequencies, Prajwal M. Kasturi
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Linearly polarized electromagnetic waves traveling through cold magnetized plasma experience Faraday rotation. The Appleton Hartree dispersion equation relates the phase shift on any electromagnetic ray to the magnetic field B, ion-electron density Ne and the angle the ray makes with the instantaneous magnetic field. This work uses the dispersion relation to calculate small time scale magnetic perturbations in the ionosphere due to electrojet current systems. The ionosphere is modeled as a collision free cold plasma with synthesized small scale magnetic perturbations. The work presented here simulates test cases, where the satellites transmits three amateur satellite radio band frequencies …
Reversible Mn Segregation At The Polar Surface Of Lithium Tetraborate,
2013
Air Force Institute of Technology
Reversible Mn Segregation At The Polar Surface Of Lithium Tetraborate, Christina L. Dugan, Robert L. Hengehold, Stephen R. Mchale, Juan A. Colon Santana, John W. Mcclory, Volodymyr T. Adamiv, Yaroslav V. Burak, Ya B. Losovyj, Peter A. Dowben
Faculty Publications
We find Mn surface segregation for single crystals of Mn doped Li2B4O7, nominally Li1.95Mn0.05B4O7(001), but as the temperature increases, evidence of this Mn surface segregation diminishes significantly. At room temperature, the surface photovoltaic charging is significant for this pyroelectric material but is quenched at a temperature well below that seen for the undoped Li2B4O7 samples. The suppression of surface charging in the region of 120 °C that accompanies the temperature of Mn dissolution in the bulk of Li2B4 …
Photoacoustic Detection Of Terahertz Radiation For Chemical Sensing And Imaging Applications,
2013
Air Force Institute of Technology
Photoacoustic Detection Of Terahertz Radiation For Chemical Sensing And Imaging Applications, Stjepan Blazevic
Theses and Dissertations
The main research objective is the development of photoacoustic sensor capable of detecting weak terahertz (THz) electromagnetic radiation. The feasibility of THz remote sensing is seen in the utilization of Microelectromechanical systems (MEMS) cantilever-based sensor. The overall sensing functionality of the detector in development is based on the photoacoustic spectroscopy and direct piezoelectric effect phenomena, as a result of which significant part of investigation has been conducted in the areas of terahertz electromagnetic radiation and its detection. The main focus of this research work was the detector analytical and Finite Element Method (FEM) simulation modeling, involving necessary material properties investigations …
Constitutive Parameter Measurement Using Double Ridge Waveguide,
2013
Air Force Institute of Technology
Constitutive Parameter Measurement Using Double Ridge Waveguide, Nathan J. Lehman
Theses and Dissertations
Electromagnetic materials characterization is important in the design of systems that interact with electromagnetic waves. Determining the constitutive parameters of a material is a vast area of research and practice. For this paper, discussion will focus on a destructive method using waveguides in the frequency range of 6-18 GHz. Traditional methods to perform similar measurements include using coaxial cable, stripline, focus beam and rectangular waveguides. This work will use Double Ridged Waveguide (DRWG) to compare to these other methods and will discuss the attributes and drawbacks of this new approach. The most similar method utilizes rectangular waveguide, so the primary …
Examining The Validity Of Using A Gaussian Schell-Model Source To Model The Scattering Of A Fully Coherent Gaussian Beam From A Rough Impedance Surface,
2013
Air Force Institute of Technology
Examining The Validity Of Using A Gaussian Schell-Model Source To Model The Scattering Of A Fully Coherent Gaussian Beam From A Rough Impedance Surface, Santasri Basu, Milo W. Hyde Iv, Salvatore J. Cusumano, Michael A. Marciniak, Steven T. Fiorino
Faculty Publications
Military applications that use adaptive optics (AO) often require a point source beacon at the target to measure and correct for wavefront aberrations introduced by atmospheric turbulence. However, turbulence prevents the formation of such a point beacon. The extended beacons that are created instead have finite spatial extents and exhibit varying degrees of spatial coherence. Modeling these extended beacons using a Gaussian Schell-model (GSM) form for the autocorrelation function would be a convenient approach due to the analytical tractability of Gaussian functions. We examine the validity of using such a model by evaluating the field scattered from a rough impedance …
Thermal And Electrical Transport In Ferromagnetic Metal Thin Films,
2013
University of Denver
Thermal And Electrical Transport In Ferromagnetic Metal Thin Films, Azure D. Avery
Electronic Theses and Dissertations
The recent emergence of spin caloritronics has focused considerable attention on the interplay between spin, charge, and temperature gradients in magnetic materials. A reliable and energy efficient method for generating pure spin currents would signify an important step toward future spin-based nano-electronics that may offer lower power consumption and greater processing capabilities. To develop new technology using thermoelectric effects in magnetic thin films, it is essential to understand thermal and electrical transport through these films. One possible source of pure spin currents is the so-called spin Seebeck effect (SSE) in which a thermal gradient (∇T) applied to a ferromagnet is …
Biparametric Analyses Of Charge Trapping In Cd0.9Zn0.1Te Based Virtual Frisch Grid Detectors,
2013
University of South Carolina - Columbia
Biparametric Analyses Of Charge Trapping In Cd0.9Zn0.1Te Based Virtual Frisch Grid Detectors, S. K. Chaudhuri, K. J. Zavalla, R. M. Krishna, K. C. Mandal
Faculty Publications
No abstract provided.
3-D Terahertz Synthetic-Aperture Imaging And Spectroscopy,
2013
Portland State University
3-D Terahertz Synthetic-Aperture Imaging And Spectroscopy, Samuel C. Henry
Dissertations and Theses
Terahertz (THz) wavelengths have attracted recent interest in multiple disciplines within engineering and science. Situated between the infrared and the microwave region of the electromagnetic spectrum, THz energy can propagate through non-polar materials such as clothing or packaging layers. Moreover, many chemical compounds, including explosives and many drugs, reveal strong absorption signatures in the THz range. For these reasons, THz wavelengths have great potential for non-destructive evaluation and explosive detection. Three-dimensional (3-D) reflection imaging with considerable depth resolution is also possible using pulsed THz systems. While THz imaging (especially 3-D) systems typically operate in transmission mode, reflection offers the most …
Insertion Of Lithium Ions Into Tio2 (Rutile) Crystals: An Electron Paramagnetic Resonance Study Of The Li-Associated Ti3+ Small Polaron,
2013
Air Force Institute of Technology
Insertion Of Lithium Ions Into Tio2 (Rutile) Crystals: An Electron Paramagnetic Resonance Study Of The Li-Associated Ti3+ Small Polaron, A. T. Brant, Nancy C. Giles, Larry E. Halliburton
Faculty Publications
Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify a Ti3+-Li+ complex in TiO2 crystals having the rutile structure. This defect consists of an interstitial Li+ ion adjacent to a substitutional Ti3+ ion (the unpaired electron on the Ti3+ ion provides charge compensation for the Li+ ion). The neutral Ti3+-Li+ complex is best described as a donor-bound small polaron and is similar in structure to the recently reported neutral fluorine and hydrogen donors in TiO2 (rutile). Lithium ions are diffused into the crystals at …
Femtosecond Filament Interaction As A Probe For Molecular Alignment,
2013
University of Central Florida
Femtosecond Filament Interaction As A Probe For Molecular Alignment, Erik Mckee
Electronic Theses and Dissertations
Femtosecond laser filamentation is a highly nonlinear propagation mode. When a laser pulse propagates with a peak power exceeding a critical value Pcr (5 GW at 800 nm in air), the Kerr effect tends to collapse the beam until the intensity is high enough to ionize the medium, giving rise to plasma defocusing. A dynamic competition between these two effects takes place leaving a thin and weakly ionized plasma channel in the trail of the pulse. When an ultrafast laser pulse interacts with molecules, it will align them, spinning them about their axis of polarization. As the quantum rotational wave …
Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer,
2013
Air Force Research Laboratory
Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer, William K. Lewis, C. G. Rumchik, M. J. Smith, K. A. Shiral Fernando, Christopher A. Crouse, Jonathan E. Spowart, Elena A. Guliants, Christopher E. Bunker
Electrical and Computer Engineering Faculty Publications
Aluminum nanoparticles and explosive formulations that incorporate them have been a subject of ongoing interest due to the potential of aluminum particles to dramatically increase energy content relative to conventional organic explosives. We have used time-resolved atomic and molecular emission spectroscopy to monitor the combustion of aluminum nanoparticles within the overall chemical dynamicsof post-detonation fireballs. We have studied the energy release dynamics of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) charges incorporating three types of aluminum nanoparticles: commercial oxide-passivated nanoparticles, oleic acid-capped aluminum nanoparticles (AlOA), and nanoparticles in which the oxide shell of the particle has been functionalized with an acrylic monomer and copolymerized into …
Using Multi-Processors To Reconstruct Images With Proton Computed Tomography,
2013
California State University, San Bernardino
Using Multi-Processors To Reconstruct Images With Proton Computed Tomography, Chenwei Xu
Theses Digitization Project
This project will employ the use of multi-processor technology to reconstruct image data as fast as possible. Two-dimensional image reconstruction technique reconstructs images by solving a linear equation: A x x =b, where A is the path matrix of proton histories, b is electron matrix of the image, and x is the matrix of image. One row in matrix A represents one beam. Matrix A consists of a number of beam projections to the image, and each projection consists of a number of beams. Contains source code.
External Cavity Mode-Locked Semiconductor Lasers For The Generation Of Ultra-Low Noise Multi-Gigahertz Frequency Combs And Applications In Multi-Heterodyne Detection Of Arbitrary Optical Waveforms,
2013
University of Central Florida
External Cavity Mode-Locked Semiconductor Lasers For The Generation Of Ultra-Low Noise Multi-Gigahertz Frequency Combs And Applications In Multi-Heterodyne Detection Of Arbitrary Optical Waveforms, Josue Davila-Rodriguez
Electronic Theses and Dissertations
The construction and characterization of ultra-low noise semiconductor-based mode-locked lasers as frequency comb sources with multi-gigahertz combline-to-combline spacing is studied in this dissertation. Several different systems were built and characterized. The first of these systems includes a novel mode-locking mechanism based on phase modulation and periodic spectral filtering. This mode-locked laser design uses the same intra-cavity elements for both mode-locking and frequency stabilization to an intra-cavity, 1,000 Finesse, Fabry-Pérot Etalon (FPE). On a separate effort, a mode-locked laser based on a Slab-Coupled Optical Waveguide Amplifier (SCOWA) was built. This system generates a pulse-train with residual timing jitter of
Metrology Of Volume Chirped Bragg Gratings Recorded In Photo-Thermo-Refractive Glass For Ultrashort Pulse Stretching And Compressing,
2013
University of Central Florida
Metrology Of Volume Chirped Bragg Gratings Recorded In Photo-Thermo-Refractive Glass For Ultrashort Pulse Stretching And Compressing, Christopher Lantigua
Electronic Theses and Dissertations
Chirped Bragg gratings (CBGs) recorded in photo-thermo-refractive (PTR) glass provide a very efficient and robust way to stretch and compress ultra-short laser pulses. These gratings offer the ability to stretch pulses from hundreds of femtoseconds, to the order of 1 ns and then recompress them. However, in order to achieve pulse stretching of this magnitude, 100 mm thick CBGs are needed. Using these CBGs to both stretch, and re-compress the pulse thus requires propagation through 200 mm of optical glass. This therefore demands perfect control of the glass homogeneity, as well as the holographic recording process of the CBG. In …
