Electromagnetics and Photonics Commons^™

Graphene As A Shielding Material For Sar Reduction In Human Head Using Rectangular And Circular Patch Antenna, Alka Singla Er., Anupma Marwaha Dr., Sanjay Marwaha Dr.

Karbala International Journal of Modern Science

Nanomaterials pave the way for better performance in wireless applications due to their unique properties. Nowadays, these have been used as shield material in dipole antennas for a solution of reduction in SAR value. This work proposes the use of emerging graphene nanomaterial by comparing the performance for two different shapes of patch antenna namely rectangular and circular patch. With the growth in technology, the protection of human health is also mandatory so the work is planned to use graphene as a shielding material for SAR reduction in the human brain and it is proved that for rectangular and circular …

Review And Analysis Of Methods For Measuring Concentration Of Suspended Substances And Active Sludge During Biological Treatment Of Waste Water, Maxsud Maxmudov, Siroj Nurov, Zafar Qo'ziev, Sanjar Sidiqov

Scientific-technical journal

This work analyzes and compares the measuring and technical characteristics of methods for measuring and controlling the parameters of activated sludge in the processes of biological wastewater treatment. As methods for measuring the concentration of activated sludge, methods such as the optical method, the ultrasonic method and the method for measuring the nuclear density of a liquid are considered. The principles of operation of each of these methods are illustrated with graphic drawings for more clarity of the interaction of the measuring signal with the particles of the measured medium. At the end of the work, conclusions on the characteristics …

Led-Based Solar Simulator, Jonathan E. Honrada

Electrical Engineering

Solar simulators are great laboratory tools that help users conduct tests with solar cells indoors. Conventional solar simulators typically use xenon arc bulbs as a light source, which can have considerable disadvantages. Recent projects have sought to design and implement LED-based solar simulators, as they are more power-efficient, inexpensive, and durable.

Based on these advantages, the goal of this project is to create an LED-based solar simulator that can replicate the characteristics of solar light, but also be tunable with controls. This broadens the testing capabilities of the device, allowing users to conduct tests with more narrow spectrums of light …

Ultra-High-Energy Neutrino Detection Antenna Simulations, Nicholas C. Garcia

Electrical Engineering

Neutrinos allow researchers to investigate high-energy galactic phenomena, such as supernovae and black holes. Neutrinos interact with their surroundings via the weak nuclear force and therefore, travel unattenuated through space and are not deflected by electromagnetic fields. However, they do rarely interact with other particles. When neutrinos interact with nucleons (protons or neutrons) in a dielectric medium (i.e.: ice sheets), they are detectable through a cone of coherent electromagnetic radiation (Askaryan Radiation) created by the particle shower generated from the neutrino interaction [1]. The Radio Neutrino Observatory in Greenland (RNO-G) detects UHE neutrinos greater than 100 PeV (10¹⁵ eV) …

Understanding Diffusion And Electrochemical Reduction Of Li+ Ions In Liquid Lithium Metal Batteries, Witness Martin, Yang Tian, Jie Xiao

Chemistry & Biochemistry Faculty Publications and Presentations

Lithium metal has drawn significant interest as an anode material for next generation lithium (Li) batteries. However, due to its propensity to form dendrites in commonly used electrolytes during repeated cycling, it has not yet been commercialized in secondary batteries. The formation of a Li protrusion is determined by the relative speed of Li+ ions being reduced and how fast they can be replenished in the vincinity of electrode. However, it is very difficult to quantify such kinetic parameters of Li+ ion in different electrolytes, not mentioning the identification of the desired electrolyte recipe to mitigate Li dendrite formation. Herein, …

Pepblock Builder Vr – An Open-Source Tool For Gaming-Based Bio-Edutainment In Interactive Protein Design, Venkata V. B. Yallapragada, Tianshu Xu, Sidney P. Walker, Sabin Tabirca, Mark Tangney

Cappa Publications

Proteins mediate and perform various fundamental functions of life. This versatility of protein function is an attribute of its 3D structure. In recent years, our understanding of protein 3D structure has been complemented with advances in computational and mathematical tools for protein modelling and protein design. 3D molecular visualisation is an essential part in every protein design and protein modelling workflow. Over the years, stand-alone and web-based molecular visualisation tools have been used to emulate three-dimensional view on computers. The advent of virtual reality provided the scope for immersive control of molecular visualisation. While these technologies have significantly improved our …

Self-Breakdown Study Of Spherical Electrodes In Air Spanning Pressures From Atmosphere To 2000 Psia, And Stress Times From Seconds To Nanoseconds, Joseph G. Felix

Electrical and Computer Engineering ETDs

In this research, a self-breakdown switch with 12.7 mm diameter spherical electrodes and a 380-micron gap was assembled and the effect of pressure and stress time on breakdown voltage and closure time were measured. Specifically, the pressure was varied from atmosphere to 2000 psia and the stress time was varied from seconds to nanoseconds. Few studies have investigated equivalent ranges of pressure and charge times on sub millimeter gap switches with electric field intensities reaching 2 MV/cm. The correlation of the parameters and switch behavior are explored in this study. In addition, the effects of humidity and electrode surface deformities …

A Comprehensive Study On Printed Circuit Board Backdoor Coupling In High Intensity Radiated Fields Environments, Ryan Patrick Tortorich

LSU Doctoral Dissertations

Due to the prevalence of unintentional electromagnetic interference (EMI) and the growth of intentional electromagnetic interference (IEMI) or high power microwave (HPM) sources, it is now more important than ever to understand how electronic systems are affected by high intensity radiated fields (HIRF) environments. Both historic events and experimental testing have demonstrated that HIRF environments are capable of disrupting and potentially damaging critical systems including but not limited to civil and military aircraft, industrial control systems (ICS), and internet of things (IoT) devices. However, there is limited understanding on the complex electromagnetic interactions that lead to such effects. This study …

Optoelectronic Valley-Spin Qubits With Ambipolar Quantum Dots, Jeremy Tull

Electrical Engineering Undergraduate Honors Theses

The current limitations of qubit-based processors are caused by imperfections in quantum gates, leading to a lack of gate fidelity. Gate fidelity can be refined by extending the coherence of qubits and reducing logic operation speed. A potential solution is to develop a hybrid qubit that has the coherence of electrically-controlled quantum dots and the gate speed of their optically-controlled counterparts. Quantum bits that utilize ultrafast optical gating to perform gate operations require precise control of the gating pulse duration. Optical dispersion can cause adverse effects pulse duration, such as pulse broadening, so dispersion-compensation techniques must be employed; by properly …

Quantum Dynamical Phenomena In Non-Hermitian And Magnomechanical Systems, Saeid Vashahri Ghamsari

Graduate Theses and Dissertations

In this dissertation, we have investigated quantum dynamics via three case studies. First, we studied a system of two coupled waveguides respectively carrying optical damping and optical gain in addition to squeezing elements in one or both waveguides. Such a system is expected to generate highly entangled light fields in the two waveguides. We, however, show that the degree of the created entanglement is significantly affected by the quantum noises associated with the amplification and dissipation. Because of the noise effect, one can only have nonzero entanglement for a limited time interval. Second, we generalized the first project by considering …

Characterization Of Gesn Semiconductors For Optoelectronic Devices, Hryhorii Stanchu

Graduate Theses and Dissertations

Germanium-tin alloys with Sn compositions higher than 8 at. % to 10 at. % have recently attracted significant interest as a group IV semiconductor that is ideal for active photonics on a Si substrate. The interest is due to the fact that while at a few percent of Sn, GeSn is an indirect bandgap semiconductor, at about 8 to 10 at. % Sn, GeSn transitions to a direct bandgap semiconductor. This is at first surprising since the solid solubility of Sn in Ge under equilibrium growth conditions is limited to only about 1 at. %. However, under non-equilibrium growth conditions, …

Si-Based Germanium Tin Photodetectors For Infrared Imaging And High-Speed Detection, Huong Tran

Graduate Theses and Dissertations

Infrared (IR) radiation spans the wavelengths of the windows: (1) near-IR region ranging from 0.8 to 1.0 μm, (2) shortwave IR (SWIR) ranging from 1.0 to 3.0 μm, (3) mid-wave IR (MWIR) region covering from 3.0 to 5.0 μm, (4) longwave IR (LWIR) spanning from 8.0 to 12.0 μm, and (5) very longwave IR extending beyond 12.0 μm. The MWIR and LWIR regions are important for night vision in the military, and since the atmosphere does not absorb at these wavelengths, they are also used for free-space communications and astronomy. Automotive and defect detection in the food industry and electronic …

Analysis Of Photodetector Based On Zinc Oxide And Cesium Lead Bromide Heterostructure With Interdigital Metallization, Tanveer Ahmed Siddique

Graduate Theses and Dissertations

In this thesis, photodetector based on the zinc oxide and cesium lead bromide hetero structure were fabricated and characterized. Zinc oxide (ZnO) nanoparticles were synthesized using solution processing and cesium lead bromide (CsPbBr3) thin film was synthesized using two step deposition method. Three phonon modes were obtained by the Raman spectroscopy of ZnO nanoparticles. X-ray diffraction spectra of ZnO exhibits five exciton peaks which denotes that the synthesized ZnO structure was of good crystallinity with wurtzite hexagonal phase. The absorbance spectrum of ZnO shows the bandgap (Eg) in the order of 3.5 eV that aligns with reported results. The photoluminescence …

A Magneto-Mechanical Piezoelectric Energy Harvester Designed To Scavenge Ac Magnetic Field From Thermal Power Plant With Power-Line Cables, Quan Wang, Kyung-Bum Kim, Sang-Bum Woo, Yooseob Song, Tae-Hyun Sang

Civil Engineering Faculty Publications

Piezoelectric energy harvesters have attracted much attention because they are crucial in portable industrial applications. Here, we report on a high-power device based on a magneto-mechanical piezoelectric energy harvester to scavenge the AC magnetic field from a power-line cable for industrial applications. The electrical output performance of the harvester (×4 layers) reached an output voltage of 60.8 V_max, an output power of 215 mW_max (98 mW_rms), and a power density of 94.5 mW_max/cm³ (43.5 mW_rms/cm³) at an impedance matching of 5 kΩ under a magnetic field of 80 …

Theory And Application Of Dielectric Rod Antennas And Arrays, Gabriel Saffold

USF Tampa Graduate Theses and Dissertations

Dielectric rods have been used for many years as waveguides and radiators. Their low loss as a transmission line and tendency to radiate at discontinuities have proven useful in applications ranging from fiber optic cables to naval fire control radar. Although this technology is well es- tablished, advances in additive manufacturing techniques and associated materials combined with the ubiquity of wireless communications and their shift to higher frequencies have generated re- newed interest in dielectric rods. Dielectric rod antennas have moderate gain and less conductive loss at higher frequencies. Similar to other surface wave antennas, they can achieve broadband performance.This …

Impact Of Hurricane Michael (2018) On Local Vertical Total Electron Content, Joanna E.S. Williams, Robert C. Tournay, H. Rose Tseng, Daniel J. Emmons Ii, Omar A. Nava

Faculty Publications

An analysis of vertical total electron content (TEC) estimates from the MIT Madrigal database is performed for the regions surrounding the eye of Hurricane Michael (2018). Absolute and detrended TEC values show a noticeable increase during the tropical cyclone (TC) relative to fluctuations at the same locations prior to the storm. Direct comparisons of TEC perturbation magnitudes to the number of lightning flashes in latitude-longitude boxes surrounding the eye of Hurricane Michael for each 5 min period of 10 October 2018 showed no visible trends. A similar comparison of the vertical TEC fluctuations with respect to the rainfall rates showed …

A Reconfigurable Stretchable Liquid Metal Antenna, Phase Shifter, And Array For Wideband Applications, David M. Hensley

Electrical and Computer Engineering ETDs

While liquid metals, such as mercury, have been used in electronics for quite some time, the non-toxic gallium based liquid metals have caused an increase in research for liquid metal applications. Some of the potential applications that have been previously presented range from reconfigurable antennas, strain and pressure sensors, and speakers and microphones to name a few. The focus of this work is to provide further research into the use of gallium based liquid metals as a reconfigurable antenna, a phase shifter, and an array. This is done by designing, constructing, and characterizing each of these reconfigurable liquid metal (LM) …

Experimental Validation Of A 3d-Printed Millimeter Wave/Thz Power Combiner, Jacob C. Giese

Electrical and Computer Engineering ETDs

The terahertz band (THz) in the electromagnetic spectrum is an untapped resource that possesses unique features for nondestructive methods of material imaging and detection. However, little advancements have been made in regard to a practical long range portable THz device. The solution proposed is an oversized cylindrical waveguide termed Power Combiner, designed to combine 12 azimuthally aligned rectangular waveguides to produce power levels suitable for threat detection at secure distances. This paper explores the physical parameters of the power combiner and the power distribution network and creates the 12 signals that allow for modification at the input of the power …

On The Dynamic Generation Of Megagauss-Level Magnetic Fields On 100-Ns Timescales To Stabilize And Magnetize Pulsed-Power-Driven Liner Implosions, Gabriel A. Shipley

Electrical and Computer Engineering ETDs

This dissertation presents analysis of experiments and simulations executed to develop the auto-magnetizing liner concept (AutoMag) for use as an alternative premagnetization mechanism for MagLIF. Tests of each stage of AutoMag (magnetization, dielectric breakdown, and implosion) were executed on the Mykonos accelerator and the Z accelerator. Experiments demonstrate strong peak axial magnetic field production (20 – 150 T), dielectric breakdown initiation that depends on global induced electric field across the target, and a level of cylindrical implosion uniformity high enough to be useful for prospective fusion-fuel-filled (auto-magnetized MagLIF) experiments.

This dissertation also presents detailed simulations of the Solid Liner Dynamic …

Computational_Electromagnetic Modeling (Cem) Of Foliage Penetration (Fopen), Monica R. Jaramillo

Electrical and Computer Engineering ETDs

Foliage penetration (FOPEN) radar at lower frequencies (UHF, VHF) is a well-studied area with a wide set of contributions. However, there is growing interest in using higher Ku-band frequencies (12-18 GHz frequency range) for FOPEN. In particular, the reduced wavelength sizes (centimeters range) provide some key saliencies for developing more optimized foliage detection solutions. The disadvantage is that exploiting Ku-band for FOPEN is complicated because higher frequencies have much more pronounced scattering effects due to their smaller wavelengths. Despite these challenges, certain foliage characteristics and signal parameters can help improve electromagnetic (EM) wave penetration in the Ku-band such as foliage …

Guest Editorial: Edge Intelligence For Beyond 5g Networks, Yan Zhang, Zhiyong Feng, Hassnaa Moustafa, Feng Ye, Usman Javaid, Chunfen Cui

Electrical and Computer Engineering Faculty Publications

Beyond fifth-generation (B5G) networks, or so-called "6G", is the next-generation wireless communications systems that will radically change how Society evolves. Edge intelligence is emerging as a new concept and has extremely high potential in addressing the new challenges in B5G networks by providing mobile edge computing and edge caching capabilities together with Artificial Intelligence (AI) to the proximity of end users. In edge intelligence empowered B5G networks, edge resources are managed by AI systems for offering powerful computational processing and massive data acquisition locally at edge networks. AI helps to obtain efficient resource scheduling strategies in a complex environment with …

Specification, Control, And Applications Of Z-Source Circuit Breakers For The Protection Of Dc Power Networks, Sagar Bhatta

Electrical & Computer Engineering Theses & Dissertations

There is a highly-increasing demand for the DC power transmission and distribution in modern power systems for the integration of newly-installed renewable energy resources and storage systems to the existing utilities. Application of DC power systems in electric ships, battery energy devices, high-voltage DC networks, smart grids, electric vehicles, microgrids, and wind farms is a recent trend that is being highly investigated. The fault protection of DC systems is an essential but challenging issue that needs careful attention to maintain system operation reliability and device safety. In this research, the specification, control, and application of Z-source breakers (ZCBs) are investigated …

Twisted Spatiotemporal Optical Vortex Random Fields, Milo W. Hyde Iv

Faculty Publications

We present twisted spatiotemporal optical vortex (STOV) beams, which are partially coherent light sources that possess a coherent optical vortex and a random twist coupling their space and time dimensions. These beams have controllable partial coherence and transverse orbital angular momentum (OAM), which distinguishes them from the more common spatial vortex and twisted beams (known to carry longitudinal OAM) in the literature and should ultimately make them useful in applications such as optical communications and optical tweezing. We present the mathematical analysis of twisted STOV beams, deriving the mutual coherence function and linear and angular momentum densities. We simulate the …

Wavefront-Selective Fano Resonant Metasurfaces, Adam C. Overvig, Andrea Alù

Advanced Science Research Center

Fano resonances are conventionally understood as sharp spectral features with selectivity in the momentum-frequency domain, implying that they can be excited only by plane waves with specific frequencies and incident angles. We demonstrate that Fano resonances can be made generally selective in the space-frequency domain. They can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. Although in conventional Fano systems this trivially occurs for normally incident plane waves, we show that, in general, the selected …

Color-Compressive Bilateral Filter And Nonlocal Means For High-Dimensional Images, Christina Karam, Kenjiro Sugimoto, Keigo Hirakawa

Electrical and Computer Engineering Faculty Publications

We propose accelerated implementations of bilateral filter (BF) and nonlocal means (NLM) called color-compressive bilateral filter (CCBF) and color-compressive nonlocal means (CCNLM). CCBF and CCNLM are random filters, whose Monte-Carlo averaged output images are identical to the output images of conventional BF and NLM, respectively. However, CCBF and CCNLM are considerably faster because the spatial processing of multiple color channels are combined into a single random filtering process. This implies that the complexity of CCBF and CCNLM is less sensitive to color dimension (e.g., hyperspectral images) relatively to other BF and NLM methods. We experimentally verified that the execution time …

Deep Learning For Anisoplanatic Optical Turbulence Mitigation In Long-Range Imaging, Matthew A. Hoffmire, Russell C. Hardie, Michael A. Rucci, Richard Van Hook, Barry K. Karch

Electrical and Computer Engineering Faculty Publications

We present a deep learning approach for restoring images degraded by atmospheric optical turbulence. We consider the case of terrestrial imaging over long ranges with a wide field-of-view. This produces an anisoplanatic imaging scenario where turbulence warping and blurring vary spatially across the image. The proposed turbulence mitigation (TM) method assumes that a sequence of short-exposure images is acquired. A block matching (BM) registration algorithm is applied to the observed frames for dewarping, and the resulting images are averaged. A convolutional neural network (CNN) is then employed to perform spatially adaptive restoration. We refer to the proposed TM algorithm as …

Modeling Aircraft Disturbance Fields For Magnetic Navigation Using Dense Anns And The Novel Manntl Architecture, Kyle A. Emery

Theses and Dissertations

The ability to use GPS for navigation is becoming increasingly limited in certain areas of the world. Knowing this, the Air Force Research Labs is constantly looking for ways to improve alternate navigation methods such as magnetic navigation. In the interest of making advancements in aircraft disturbance field modelling, Lieutenant Emery recreates models from previous works to prove results. Lieutenant Emery also introduces a novel model architecture that attempts to mix the filtering properties of Tolles-Lawson with the non-linear capabilities of an artificial neural network. The introduction of this model could present better aircraft disturbance field modelling and in turn, …

Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland

Theses and Dissertations

Forecasting of solar flares remains a challenge due to the limited understanding of the triggering mechanisms associated with magnetic reconnection, the primary physical phenomenon connected to these events. Consequently, methods continue to rely on the climatology of solar flare events as opposed to the underlying physics principles. Models of magnetic reconnection in the solar atmosphere places the null point of the reconnection within the corona. Though as of now the coronal magnetic field cannot be directly measured, the field is tied to the photospheric magnetic field, which can be. This study utilized data from the Solar Dynamics Observatory Helioseismic and …

Real-Time Aerial Magnetic And Vision-Aided Navigation, Daniel J. Clarke

Theses and Dissertations

Aerial magnetic navigation has shown to be a viable alternative navigation method that has the potential for world-wide availability, to include over oceans. Obtaining GPS-level accuracy using magnetic navigation alone is challenging, but magnetic navigation can be combined with other alternative navigation methods that are more posed to obtaining GPS-level accuracy in their current state. This research presents an aerial navigation solution combining magnetic navigation and vision-aided navigation to aid an inertial navigation system (INS). The navigation solution was demonstrated in real-time playback using simulated magnetic field measurements and flight-test captured visual imagery. Additionally, the navigation solution was flight-tested on …

Computational Electromagnetic Modeling Of Metasurface Optical Devices With Defect Study, Carlos D. Diaz

Theses and Dissertations

One of the first fabricated metasurface optical devices, the in-plane V-antenna lenses, were plagued by a fundamental transmission limit (<25 >). Two distinct sets of Out-of-Plane phase elements were designed with improved transmission (~60 ). These were fabricated as beamsteerers and characterized in terms of their Bidirectional Transmittance Distribution Function measured as a function of scatter angle. Experimental data from the beamsteerers was analyzed via simulations using a finite element method (FEM). The measurements showed the designed beamsteering, but also a strong zero-order diffraction not present in the simulations, which motivated this study to understand what was causing these differences. …