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- 3D perception (1)
- Catadioptrics (1)
- Free space optical communication (1)
- Harmful algal blooms (1)
- Hybrid perovskites (1)
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- Karenia brevis (1)
- Micro Aerial Vehicles (MAVs) (1)
- Neural networks (1)
- Normalized fluorescence height (1)
- Ocean color remote sensing reflectance (1)
- Omnistereo (1)
- Optical fiber communication (1)
- Optical vortex (1)
- Orbital angular momentum (1)
- Perovskite solar cells (1)
- Retrieved chlorophyll-a (1)
- Thin-film photovoltaic technology (1)
- West Florida Shelf (1)
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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Vector Beams For Fundamental Physics And Applications, Giovanni Milione
Vector Beams For Fundamental Physics And Applications, Giovanni Milione
Dissertations, Theses, and Capstone Projects
Lights salient degrees of freedom are the independent parameters that completely de- scribe an electromagnetic wave (in the paraxial approximation) and include polarization, wavelength, and time. Most recently, lights space degree of freedom has received sig- nificant attention via the sub-discipline of optics that can be referred to as complex light or structured light. The study of complex light is a veritable renaissance of optics; us- ing lights space degree of freedom many classical optics phenomena have been revisited with novel results. In this thesis, a novel form of structured light referred to as vector beams will be investigated. It …
Light-Activated Photocurrent Degradation And Self-Healing In Perovskite Solar Cells, Wanyi Nie, Jean-Christophe Blancon, Amanda J. Neukirch, Kannatassen Appavoo, Hsinhan Tsai, Manish Chhowalla, Muhammad A. Alam, Matthew Y. Sfeir, Claudine Katan, Jacky Even, Sergei Tretiak, Jared J. Crochet, Gautam Gupta, Aditya D. Mohite
Light-Activated Photocurrent Degradation And Self-Healing In Perovskite Solar Cells, Wanyi Nie, Jean-Christophe Blancon, Amanda J. Neukirch, Kannatassen Appavoo, Hsinhan Tsai, Manish Chhowalla, Muhammad A. Alam, Matthew Y. Sfeir, Claudine Katan, Jacky Even, Sergei Tretiak, Jared J. Crochet, Gautam Gupta, Aditya D. Mohite
Publications and Research
Solution-processed organometallic perovskite solar cells have emerged as one of the most promising thin-film photovoltaic technology. However, a key challenge is their lack of stability over prolonged solar irradiation. Few studies have investigated the effect of light soaking on hybrid perovskites and have attributed the degradation in the optoelectronic properties to photochemical or field-assisted ion migration. Here we show that the slow photocurrent degradation in thin-film photovoltaic devices is due to the formation of light-activated meta-stable deep-level trap states. However, the devices can self-heal completely by resting them in the dark for <1 min or the degradation can be completely prevented by operating the devices at 0°C. We investigate several physical mechanisms to explain the microscopic origin for the formation of these trap states, among which the creation of small polaronic states involving localized cooperative lattice strain and molecular orientations emerges as a credible microscopic mechanism requiring further detailed studies.
Satellite Retrievals Of Karenia Brevis Harmful Algal Blooms In The West Florida Shelf Using Neural Networks And Comparisons With Other Techniques, Ahmed El-Habashi, Ioannis Ioannou, Michelle Tomlinson, Richard P. Stumpf, Sam Ahmed
Satellite Retrievals Of Karenia Brevis Harmful Algal Blooms In The West Florida Shelf Using Neural Networks And Comparisons With Other Techniques, Ahmed El-Habashi, Ioannis Ioannou, Michelle Tomlinson, Richard P. Stumpf, Sam Ahmed
Publications and Research
We describe the application of a Neural Network (NN) previously developed by us, to the detection and tracking, of Karenia brevis Harmful Algal Blooms (KB HABs) that plague the coasts of the West Florida Shelf (WFS) using Visible Infrared Imaging Radiometer Suite (VIIRS) satellite observations. Previous approaches for the detection of KB HABs in the WFS primarily used observations from the Moderate Resolution Imaging Spectroradiometer Aqua (MODIS-A) satellite. They depended on the remote sensing reflectance signal at the 678 nm chlorophyll fluorescence band (Rrs678) needed for both the normalized fluorescence height (nFLH) and Red Band Difference algorithms (RBD) currently used. …
Design And Analysis Of A Single-Camera Omnistereo Sensor For Quadrotor Micro Aerial Vehicles (Mavs), Carlos Jaramillo, Roberto G. Valenti, Ling Guo, Jizhong Xiao
Design And Analysis Of A Single-Camera Omnistereo Sensor For Quadrotor Micro Aerial Vehicles (Mavs), Carlos Jaramillo, Roberto G. Valenti, Ling Guo, Jizhong Xiao
Publications and Research
We describe the design and 3D sensing performance of an omnidirectional stereo (omnistereo) vision system applied to Micro Aerial Vehicles (MAVs). The proposed omnistereo sensor employs a monocular camera that is co-axially aligned with a pair of hyperboloidal mirrors (a vertically-folded catadioptric configuration). We show that this arrangement provides a compact solution for omnidirectional 3D perception while mounted on top of propeller-based MAVs (not capable of large payloads). The theoretical single viewpoint (SVP) constraint helps us derive analytical solutions for the sensor’s projective geometry and generate SVP-compliant panoramic images to compute 3D information from stereo correspondences (in a truly synchronous …
Band Gap Engineering Of N-Alloyed Ga2o3 Thin Films, Dongyu Song, Li Li, Bingsheng Li, Yu Sui, Aidong Shen
Band Gap Engineering Of N-Alloyed Ga2o3 Thin Films, Dongyu Song, Li Li, Bingsheng Li, Yu Sui, Aidong Shen
Publications and Research
The authors report the tuning of band gap of GaON ternary alloy in a wide range of 2.75 eV. The samples were prepared by a two-step nitridation method. First, the samples were deposited on 2-inch fused silica substrates by megnetron sputtering with NH3 and Ar gas for 60 minutes. Then they were annealed in NH3 ambience at different temperatures. The optical band gap energies are calculated from transmittance measurements. With the increase of nitridation temperature, the band gap gradually decreases from 4.8 eV to 2.05 eV. X-ray diffraction results indicate that as-deposited amorphous samples can crystallize into monoclinic and hexagonal …