Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 130 for “"electromagnetic spectrum"”.
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Development of a scanning system for use in the Terahertz region of the Electromagnetic Spectrum
… system for use in the Terahertz region of the Electromagnetic spectrum. The approach used by the prototype developed, utilises two tilting mirrors for the purposes of scanning a target under investigation. An object is scanned by tilting an incident beam of radiation to a point of interest on …
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Improving high school physical science students' understanding of the electromagnetic spectrum: a modified diagram approach
… students encounter in understanding a standard electromagnetic spectrum diagram. A research-driven, modified version of that standard diagram was used in this study to determine the value added to student understanding of electromagnetic waves. A content analysis was performed on electromagnetic …
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Examining the response of the Martian atmosphere to increases in different portions of the electromagnetic spectrum during solar flares
… to increases in different portions of the electromagnetic spectrum during solar flares. On March 24, 2015 the Mars Atmosphere and Volatile Evolution (MAVEN) mission satellite made measurements of the atmosphere and solar irradiance during a solar flare. These measurements were used by the …
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Spectral Conversion of Light Using Cadmium Selenium Zinc Sulfide Core Shell Quantum Dots to Increase the Efficiency of Photovoltaic Cells
… a silicon-based photovoltaic cell. Although the electromagnetic spectrum of the sun is broadband, only a finite portion of the spectrum can be harnessed by current solar cell technology. For example, the excess energy of ultraviolet light, when compared to the bandgap of silicon, is generally …
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Sampling time-resolved phenomena
… of sound. Depending on the sub-band of the electromagnetic spectrum, the interaction of waves or pulses with the scene of interest results in measurements and based on this proxy of the physical world, one is interested in inferring physical properties of the scene. This may be something …
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Multiple-antenna systems in ad-hoc wireless networks
… services has resulted in crowding of the electromagnetic spectrum. The "spectral-commons" model, where a portion of the electromagnetic spectrum is public and used on an ad-hoc basis, has been proposed to free up spectrum that has been allocated but underutilized. Ad-hoc wireless networks …
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An Inductively Coupled Plasma Atomic Emission Spectrometer for the Detection of Nonmetals in the Vacuum Ultraviolet
… emission in the vacuum ultraviolet region of the electromagnetic spectrum.
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Identification of Near-Uv Chromophores and Characterization of Cellular Responses to Near-Uv Damage and Oxygen Stress
… is the primary chromophore in the UV-C region of electromagnetic spectrum (100-280nm; also known as Far UV or germicidal-UV), and its interaction with UV-C has been extensively studied. However, DNA has very little absorbance in the UV-A region (315-400nm). The identification of chromophores that …
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The Middle Class Tax Relief And Job Creation Act Of 2012 And Its Impact On Television Broadcasting And Future Broadband Wireless Communications
… freeing up as much as 120 MHz of valuable electromagnetic spectrum for utilization by wireless communications providers. This "new" wireless spectrum will allow wireless providers to increase their wireless broadband capabilities and feed the ever-growing demand by consumers for more …
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Thermal and photochemical vapor deposition of aluminum nitride and gallium nitride
Currently, the optical spectrum of the III-V compound semiconductors has been largely confined, with a few notable exceptions, to the visible red-orange to infrared portion of the electromagnetic spectrum ($\sim$650 nm to $\sim$1550 nm). The AlGaN material system may be able to extend this range to …
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Tunable absorption and selective thermal emission from engineered metals with thin dielectric coatings
… is a technologically important region of the electromagnetic spectrum because it includes both the peak thermal emission of objects at room temperature and the molecular absorption resonances of many common liquids and gases. Thermal sensing and imaging is widely used in industrial and defense …
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Modeling of a compact terahertz source based on the two-stream instability.
… the microwave and infrared bands of the electromagnetic spectrum, thus combining the penetrating power of lower-frequency waves and imaging capabilities of higher-energy infrared radiation. THz radiation is employed in various fields such as cancer research, biology, agriculture, homeland …
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Defect Production in Alkali Halide Crystals by Monochromatic X and Ultraviolet Radiation (Photoluminescence, X-Ray Absorption, Spectra, Impurity)
… halides was observed in diverse parts of the electromagnetic spectrum. Using low flux monochromatic sources, this efficiency was measured in the hard x-ray region at the K-edge of bromine in KBr and in the near ultraviolet part of the spectrum corresponding to the exciton region of the alkali …
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Design, fabrication and characterization of terahertz quantum-well photodetectors
… in the fully exploration and development of electromagnetic spectrum. However, a fast and sensitive THz photodetector ready for array integration is not available. A THz Quantum-well Photodetector (QWP) has the properties of being fast, sensitive, low-noise, and narrow-band. It is promising …
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PULSED THz GENERATION BASED ON PHOTOCONDUCTIVE ANTENNA FOR THz TIME-DOMAIN SPECTROSCOPY
… (THz) wave is defined as the region of the electromagnetic spectrum with frequencies ranging from 100 GHz to 10 THz. The THz technology has many potential applications. However, it was called the “THz gap” due to the lack of efficient generation of THz waves. Therefore, the development of …
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Prediction Of Optical Properties Of Plasmonic Composites: Applications To Solar Energy Harvesting
… backscattering in the blue region of the spectrum from an Ag nanoparticle suspension could promote microalgal growth by more than 30%. This was because the photoactivity of green microalgae is non-monotonic across the electromagnetic spectrum. The wavelength and light flux of the …
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An Investigation Into the Detection and Analysis of Selected Landfills Within Central and Southwest Missouri Using Remotely Sensed Data
… reflectance data from several bands of the electromagnetic spectrum, some of which are used to detect plant vigor, barren soil, and certain plant species. Consequently, it has the potential to detect landfills and assess their physical characteristics. This research indicates that the …
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Finite-Difference and Analytic-Gradient Approaches for Simulating Vibrational Circular Dichroism Using Second-Order Møller-Plesset Perturbation Theory and Configuration Interaction
… polarized light in the infrared region of the electromagnetic spectrum. Application of this spectroscopy is primarily directed towards the elucidation of molecular absolute configuration. As a result of the complex relationships involved in light-matter interactions, theoretical simulation is …
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FEASIBILITY OF INDIRECT FIRE FOR COUNTERING SWARMS OF SMALL UNMANNED AERIAL SYSTEMS
… SUAS operations. Such a shell would target the electromagnetic spectrum vulnerabilities of Unmanned Aerial Vehicles (UAV) by utilizing expendable jammers delivered as a payload in a cargo-carrying projectile. This capability is likely to be effective against the swarm threat and can be used from …
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Real-time adaptive circuitry to support simultaneous radar and communications.
… and wireless communication systems access the electromagnetic spectrum, interference becomes more common. This interference can lead to reduced performance for the involved systems, meaning dropped calls and missed radar detections. To help mitigate this spectral congestion, this work presents …
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