Performance Analysis For Single-Stage And Multi-Stage Coreless Axial Flux Permanent Magnet Generator With Different Rotor Structures,
2020
Universiti Malaya
Performance Analysis For Single-Stage And Multi-Stage Coreless Axial Flux Permanent Magnet Generator With Different Rotor Structures, Habib Asiful
Student Works (2020-2029)
Axial flux permanent magnet (AFPM) generator is a good candidate for both low and high-speed applications. Compared to radial flux machines, AFPM generators can be easily cascaded for enhanced power/torque while maintaining a fixed machine diameter. To improve power density and reduce cogging torque, some researchers have proposed the removal of iron core in the stator of AFPM machine, giving rise to the concept of coreless AFPM machine. Nevertheless, most of these coreless machines still require back iron on the rotor and/stator to reduce leakage flux. In this project, different rotor structures for single-stage coreless AFPM generators were considered, using …
Spectral 3d Reconstruction Based On Macroscopic Oct Imaging,
2020
New Jersey Institute of Technology
Spectral 3d Reconstruction Based On Macroscopic Oct Imaging, Xingyu Zhou
Theses
Various optical technologies have been utilized to improve art conservation by art conservators, such as laser triangulation, stereophotogrammetry, structured light, laser scanner and time of flight sensors. These methods have been deployed to capture the 3D or surface topography information of sculptures and architectures. Optical coherence tomography (OCT) has introduced new imaging methods to study the surface features and subsurface structures of delicate cultural heritage objects. However, despite its higher spatial resolution, the field of view (FOV) of OCT severely limits the size of the scanning area and does not allow macroscopic examination. To solve this issue, we develop and …
Control And Locomotion Of Inertially And Magnetically Actuated Multi-Scale Robotic Systems,
2020
Southern Methodist University
Control And Locomotion Of Inertially And Magnetically Actuated Multi-Scale Robotic Systems, Ehab Al Khatib
Mechanical Engineering Research Theses and Dissertations
In this research, two actuation systems were introduced, inertial and magnetic actuation. In the inertial actuation, the robot used the transfer of momentum to navigate, and this momentum could be generated by spinning masses and wheels. Recent studies in our System Laboratory proved that a wide range of inertially actuated locomotion systems could be generated. This can be achieved by using a family tree approach, starting from a very simple system, and progressively evolving it to more complex ones. The motion diversity of these robots inspired us to extend their locomotion from a macro scale to millimeter and micro scales. …
Numerical Modeling Of Magnetic Fields For Mirror Neutron Search Experiment,
2020
University of Tennessee, Knoxville
Numerical Modeling Of Magnetic Fields For Mirror Neutron Search Experiment, Adam Johnston
Pursuit - The Journal of Undergraduate Research at The University of Tennessee
This paper will outline the configuration of 3D magnetic field model simulated from electric current sources using MATLAB. The model is using 3D arrays allowing for quick and accurate numerical approximations of Bio-Savart integrals, of error < , modeling the behavior of a magnetic field due to current carrying wires. We will discuss the development of a 3D magnetic field configuration produced by the current carrying wires around a large 2.5 m diameter vacuum beam tube in the proposed mirror neutron search experiment at High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). The simulations demonstrate that the magnetic field with uniformity better than ± 2.5 mG that will allow for optimal results in experiment within the controlled range of net magnetic field magnitudes |B| 500 mG and in the large vacuum tube along 20-m neutron flight path can be achieved for an approximately 6 cm radius section at the center of the tube.
Design And Verification Of Search Coil Inductance For Pulse Induction Metal Detection,
2020
University of Arkansas, Fayetteville
Design And Verification Of Search Coil Inductance For Pulse Induction Metal Detection, David Desrochers
Electrical Engineering Undergraduate Honors Theses
As violent attacks have increased at different venues such as schools, the need for affordable and effective metallic weapon detection has increased. Probing and scanning detection wands are the most common seen in use by guards. This project seeks to combine both probing and scanning coils into one pulse induction metal detector. The use of one drive circuit for both LC coil tank circuits further economizes the system. ANSYS Maxwell electromagnetic simulations are used to develop the geometries needed for sensitive metal detection. Analytical, simulation, and experimental methods are used to first verify the design flow for solenoid inductors. These …
Wideband And Flat-Gain Optical Amplifier With Hafnia-Bismuth Erbium Co-Doped Fiber,
2020
Universiti Malaya
Wideband And Flat-Gain Optical Amplifier With Hafnia-Bismuth Erbium Co-Doped Fiber, Abduljabbar Al-Azzawi Alabbas Ahmed
Student Works (2020-2029)
A compact optical amplifier with a flat-gain characteristic is demonstrated using hafnia bismuth-erbium co-doped fiber (HB-EDF) as the gain medium. The HB-EDF was recently fabricated using a modified chemical vapor deposition (MCVD) process in conjunction with solution doping (SD) technique. The fiber has an Erbium ions concentration of 12500 wt. ppm, which was realized due to the co-doping with Hafnium and Aluminum ions. Firstly, the proposed amplifier was investigated for both single and double-pass configurations. It is found that the 0.5m long HB-EDF is the optimum length for the C-band region. For double-pass HB-EDFA, at input signal power of -10 …
Advancing Compact Pulsed Power,
2020
University of New Mexico
Advancing Compact Pulsed Power, Jon C. Pouncey
Electrical and Computer Engineering ETDs
The first two decades of the 21st century have seen significant interest in expanding the application of pulsed power technology beyond its traditional use in physics and nuclear weapons research. Applications in the field of national defense, which present unique constraints on system size, have provided impetus to increase the exploration of compact pulsed power solutions. Innovations related to energy density, insulation, switching, and power conversion systems have been realized, bringing deployable compact pulsed power systems closer to realization than ever before. However, recent systems integration efforts have shown that work still remains to develop needed tools and technologies …
Ensemble Malware Classification System Using Deep Neural Networks,
2020
University of Dayton
Ensemble Malware Classification System Using Deep Neural Networks, Barath Narayanan Narayanan, Venkata Salini Priyamvada Davuluru
Electrical and Computer Engineering Faculty Publications
With the advancement of technology, there is a growing need of classifying malware programs that could potentially harm any computer system and/or smaller devices. In this research, an ensemble classification system comprising convolutional and recurrent neural networks is proposed to distinguish malware programs. Microsoft's Malware Classification Challenge (BIG 2015) dataset with nine distinct classes is utilized for this study. This dataset contains an assembly file and a compiled file for each malware program. Compiled files are visualized as images and are classified using Convolutional Neural Networks (CNNs). Assembly files consist of machine language opcodes that are distinguished among classes using …
Resonant Metagratings For Spectral And Angular Control Of Light For Colored Rooftop Photovoltaics,
2020
University of Amsterdam
Resonant Metagratings For Spectral And Angular Control Of Light For Colored Rooftop Photovoltaics, Floris Uleman, Andrea Cordaro, Andrea Alù, Albert Polman
Advanced Science Research Center
We designed semitransparent metagrating supercells that enable control over the spectrum and directivity of incident light for applications in photovoltaics with tailored angular appearance. The building block of the supercells is a 100–120 nm wide and 175 nm tall silicon nanowire that shows a strong Mie resonance around λ = 650 nm. By arranging the resonant Mie scatterers into metagratings of increasing pitch (675–1300 nm), we created a Lambertian-like scattering distribution over an angular range of choice. The millimeter-sized metasurfaces were fabricated using electron beam lithography and reactive ion etching. The fabricated metasurface nearly fully suppresses specular reflection on resonance …
Evaluating The Effects Of Electric And Magnetic Loading On The Performance Of Single And Double Rotor Axial Flux Pm Machines,
2020
University of Kentucky
Evaluating The Effects Of Electric And Magnetic Loading On The Performance Of Single And Double Rotor Axial Flux Pm Machines, Narges Taran, Greg Heins, Vandana Rallabandi, Dean Patterson, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Axial flux PM (AFPM) machines are used particularly in applications requiring a compact structure. Their disc shape topology and axial air-gap have led to a variety of configurations including two popular ones: the yokeless and segmented armature (YASA), and the single-stator single rotor or single sided machine. In this study, a comprehensive comparative analysis of these configurations is conducted at different magnetic and electric loadings. It is found that at lower loadings, typically employed for air-cooled machines, the torque/ampere characteristics of the YASA machine are almost identical to those of a single sided machine constructed with half the magnet volume. …
Single-Pulse, Kerr-Effect Mueller Matrix Lidar Polarimeter,
2020
Air Force Research Laboratory
Single-Pulse, Kerr-Effect Mueller Matrix Lidar Polarimeter, Keyser, Christian K., Richard K. Martin, Helena Lopez-Aviles, Khanh Nguyen, Arielle M. Adams, Demetrios Christodoulides
Faculty Publications
We present a novel light detection and ranging (LiDAR) polarimeter that enables measurement of 12 of 16 sample Mueller matrix elements in a single, 10 ns pulse. The new polarization state generator (PSG) leverages Kerr phase modulation in a birefringent optical fiber, creating a probe pulse characterized by temporally varying polarization. Theoretical expressions for the Polarization State Generator (PSG) Stokes vector are derived for birefringent walk-off and no walk-off and incorporated into a time-dependent polarimeter signal model employing multiple polarization state analyzers (PSA). Polarimeter modeling compares the Kerr effect and electro-optic phase modulator–based PSG using a single Polarization State Analyzer …
Development Of A Monolithic Implantable Neural Interface From Cubic Silicon Carbide And Evaluation Of Its Mri Compatibility,
2020
University of South Florida
Development Of A Monolithic Implantable Neural Interface From Cubic Silicon Carbide And Evaluation Of Its Mri Compatibility, Mohammad Beygi
USF Tampa Graduate Theses and Dissertations
One of the main issues with micron-sized intracortical neural interfaces (INIs) is their long-term reliability, with one major factor stemming from device material failure caused by the heterogeneous integration of multiple materials used to realize the implant. Single crystalline cubic silicon carbide (3C-SiC) is a semiconductor material that has been long recognized for its mechanical robustness and chemical inertness. It has the benefit of demonstrated biocompatibility, which makes it a promising candidate for chronically-stable, implantable INIs. In the first section of this dissertation, the fabrication and initial electrochemical characterization of a monolithic, Michigan-style 3C-SiC microelectrode array (MEA) probe is reported. …
Dynamic Micromechanical Fabry-Perot Cavity Sensors Fabricated By Multiphoton Absorption Onto Optical Fiber Tips,
2020
Air Force Institute of Technology
Dynamic Micromechanical Fabry-Perot Cavity Sensors Fabricated By Multiphoton Absorption Onto Optical Fiber Tips, Jeremiah C. Williams
Theses and Dissertations
This research leveraged two-photon polymerization microfabrication to integrate dynamic mechanical components with Fabry-Perot resonators onto the ends of low-loss optical fibers to prototype 3 micro-optic devices. The first device featured a multi-positional mirror that enabled thin-film deposition onto cavities of any length with mirrors of significant curvature, for refractive index sensing. The second device combined an FP cavity with a spring body featuring easily scalable stiffness for pressure sensing. The third device presented a high-speed rotating micro-anemometer for measuring a wide range of gas flows. All devices represent a significant reduction in size and weight over commercially available devices.
Characterization And Sensitivity Analysis Of 6 Meter Cassegrain Antenna,
2020
Air Force Institute of Technology
Characterization And Sensitivity Analysis Of 6 Meter Cassegrain Antenna, James L. Harris
Theses and Dissertations
This paper will characterize a 6 meter in diameter cassegrain antenna. The cassegrain antenna is a special form of a dual reflector antenna which uses a main reflector following a parabolic curve and a sub reflector which follows a hyperbolic curve. Cassegrain style antennas have multiple parameters which can be tuned to achieve specific design goals. Performing a sensitivity analysis will establish relationships between design parameters, directivity, side lobe levels, and effects of strut geometry. The initial design parameters will be assumed based on typical values. Results from the sensitivity analysis will be used to provide a performance band for …
Focused Beam System Biaxial Material Characterization,
2020
Air Force Institute of Technology
Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman
Theses and Dissertations
Electromagnetic material characterization is the process of determining the constitutive parameters (complex permittivity and permeability) of given a sample. Due to the large number of unknowns involved, multiple unique measurements are required for material property extraction. Many measurement methods, such as waveguides and striplines, possess a rigid internal structure that the sample being measured must adhere to. This rigidity limits these methods to samples that fit within the device and inhibits oblique sample orientations, limiting the number of independent measurements that can be obtained. A focus beam system, due to being an open system with greater freedom in sample size …
Structural And Electronic Properties Of The Pure And Stable Elemental 3d Topological Dirac Semimetal Α-Sn,
2020
CUNY Advanced Science Research Center
Structural And Electronic Properties Of The Pure And Stable Elemental 3d Topological Dirac Semimetal Α-Sn, Maya N. Nair, Ivan Madarevic, Umamahesh Thupakula, Gertjan Lippertz, Niels Claessens, Pin-Cheng Lin, Harsh Bana, Sara Gonzalez, Giovanni Di Santo, Luca Petaccia, Lino M.C. Pereira, Chris Van Haesendonck, Margriet J. Van Bael
Advanced Science Research Center
In-plane compressively strained α-Sn films have been theoretically predicted and experimentally proven to possess non-trivial electronic states of a 3D topological Dirac semimetal. The robustness of these states typically strongly depends on purity, homogeneity, and stability of the grown material itself. By developing a reliable fabrication process, we were able to grow pure strained α-Sn films on InSb(100), without heating the substrate during growth nor using any dopants. The α-Sn films were grown by molecular beam epitaxy, followed by experimental verification of the achieved chemical purity and structural properties of the film’s surface. Local insight into the surface morphology was …
Syllabus Ee330 Electromagnetics,
2020
CUNY City College
Syllabus Ee330 Electromagnetics, Nicholas Madamopoulos
Open Educational Resources
Concepts covered in the undergraduate electrical engineering class of electromagnetics
Magslam: Aerial Simultaneous Localization And Mapping Using Earth's Magnetic Anomaly Field,
2020
Air Force Institute of Technology
Magslam: Aerial Simultaneous Localization And Mapping Using Earth's Magnetic Anomaly Field, Taylor N. Lee, Aaron J. Canciani
Faculty Publications
Instances of spoofing and jamming of global navigation satellite systems (GNSSs) have emphasized the need for alternative navigation methods. Aerial navigation by magnetic map matching has been demonstrated as a viable GNSS‐alternative navigation technique. Flight test demonstrations have achieved accuracies of tens of meters over hour‐long flights, but these flights required accurate magnetic maps which are not always available. Magnetic map availability and resolution vary widely around the globe. Removing the dependency on prior survey maps extends the benefits of aerial magnetic navigation methods to small unmanned aerial systems (sUAS) at lower altitudes where magnetic maps are especially undersampled or …
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens,
2020
Air Force Institute of Technology
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv
Faculty Publications
We present a method to generate any genuine electromagnetic partially coherent source (PCS) from correlated, stochastic complex screens. The method described here can be directly implemented on existing spatial-light-modulator-based vector beam generators and can be used in any application which utilizes electromagnetic PCSs. Our method is based on the genuine cross-spectral density matrix criterion. Applying that criterion, we show that stochastic vector field realizations (corresponding to a desired electromagnetic PCS) can be generated by passing correlated Gaussian random numbers through “filters” with space-variant transfer functions. We include step-by-step instructions on how to generate the electromagnetic PCS field realizations. As an …
Detection Of Reconnection Signatures In Solar Flares,
2020
Air Force Institute of Technology
Detection Of Reconnection Signatures In Solar Flares, Taylor R. Whitney
Theses and Dissertations
Solar flare forecasting is limited by the current understanding of mechanisms that govern magnetic reconnection, the main physical phenomenon associated with these events. As a result, forecasting relies mainly on climatological correlations to historical events rather than the underlying physics principles. Solar physics models place the neutral point of the reconnection event in the solar corona. Correspondingly, studies of photospheric magnetic fields indicate changes during solar flares -- particularly in relation to the field helicity -- on the solar surface as a result of the associated magnetic reconnection. This study utilizes data from the Solar Dynamics Observatory (SDO) Helioseismic and …
