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 35 for “"g-band"”.
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Spectroscopy of small scale magnetic structures in the solar photosphere
If the sun is imaged in the G-band (a spectral range at 430nm that <br>is dominated by electronic transitions of the CH-molecule) at a <br>sufficiently high resolution, the presence of the so-called G-band <br>bright points is revealed. <br>They are interpreted as small-scale magnetic field …
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Application of adaptive optics to the spectroscopic investigation of small-scale solar structures
We study bright points, umbral dots and the G-band using a two-dimensional spectrometer and an Adaptive Optics system, which allows us to record high-resolution dopplergrams and residual intensity images. We find evidence that bright points are smaller than 120 km in diameter. Bright points are …
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Resonance Raman spectroscopy of single-walled carbon nanotubes
… the radial breathing mode, and the tangential G-band (1600cm-') associated with carbon atom displacements on the cylindrical shell of the nanotube (C-C stretching motion of the atoms). The strong coupling between electrons and phonons in this one-dimensional system furthermore gives rise to …
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Charging and defects in single-walled carbon nanotubes
… broad and asymmetric Fano lineshape in Raman G band of m-CNTs was first time evidenced. The observation that Fano component is most broadened and downshifted when Fermi level is close to the Dirac point (DP) reveals its origin as the consequence of coupling of phonon to vertical electronic …
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High resolution spectroscopy of photospheric bright points
… this thesis consists of speckle-reconstructed G-band images and quasi-simultaneous two-dimensional spectra in the neutral iron line at 557.6 nm. The choice of the G-band - a molecular bandhead at around 430 nm - for observations of photospheric bright points is motivated by their increased …
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Pulsed mm-Wave electron cyclotron maser experiments
… used to generate high power mm-waves in the W-band (75-110GHz) and the G-band (150-220GHz) frequency ranges. The relativistic electron beam (R. E. B.) was produced from a field-immersed, field-emission, cold cathode. A shaped anode cavity was designed for the optimum cavity Q, resonant …
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Functional surface chemistry of carbon-based nanostructures
… defect concentration is shown to decrease G-band phonon population lifetime and increase G-band linewidth. Doping only increases G-band linewidth, leaving non-equilibrium population decay rate unaffected. Phonon mediated electron scattering is especially strong in nanotubes making optical …
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Integrated Experimental Characterization of the Lower Huron Shale in the Central Appalachian Basin
… results show that the curve fitted G band position and the band separation between the G band and D1 band tend to increase with the rise of thermal maturity level. Results of FTIR spectroscopy show that the aromaticity level and the condensation extent of aromatic rings show an …
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Studies of solar white-light flares and small-scale magnetic structures observed in the near infrared
… observations, visible continuum and G-band images were obtained simultaneously, as well as the data from satellites, such as Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SoHO) and the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), were …
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Calibration and validation for CubeSat Microwave Radiometers
… 12-channel passive microwave radiometer in W-band, F-band, and G-band.
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The 3-D topology of magnetic fields in and around sunspots
… concentrations produce brightenings in the G band, where a lot of spectral lines of the CH molecule are present. Inside magnetic fields, the density is reduced, as the magnetic pressure contributes to the pressure balance equation. Thus, the reduced density allows to see to deeper layers of …
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Effects of Substrate and Molecular Adsorption on Raman Scattering From Individual Single -Walled Carbon Nanotubes
… disorder. Variation and complexity in the G-band of metallic nanotube Raman spectrum is explained in terms of Kohn anomalies (KAs) leading to broad and softened ALO1 phonon modes, as well as O2 induced enhancement of double resonance processes. Effects of adsorption of NH3 on Raman scattering …
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Optical Processes in Xenon: Multiphoton Ionization and Ultraviolet Photodissociation of the Dimer Ion
… on the 1( 1/2)(,u) (--->) 2( 1/2)(,g) band has been observed after sequential UV pumping. Finally, the role of Xe(,2)('+) in the formation of the excimers XeCl and Xe(,2)Cl has been examined.
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Design/System Technology Co-optimization of Gallium Nitride High Electron Mobility Transistors for Next-G 3DIC Heterogeneous Integration of Gallium Nitride and Si CMOS
… RF front ends. To design the most efficient W-G Band devices and systems, we must embrace a design/system-technology co-optimization (DTCO/STCO) approach, that combines innovative GaN transistors with engineered linearity, novel heterogeneous integration with state-of-the-art Silicon (Si) bias …
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Design Of A Material Test Kit For Use From 1.6 Ghz To 26.5 Ghz And Its Use In Evaluation Of Dielectric Properties Of Foam Core Materials Used In Sandwich Composites
… N5242-X vector network analyzer (VNA) in various bands such as R-band, S-band, C-band, G-band, C-band, X-band, P-band and K-band i.e. the dielectric properties of these materials are measured in the frequency range of 1.70 GHz to 26.5 GHz. The rectangular waveguide (RWG) is used for the …
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Electrical Response of Carbon Nanotubes Under Electrolyte
… phonons and the Fermi level lies near the band crossing point. The Fermi level dependent enhancements in noise amplitude have been correlated with Raman G-band broadening. These observations suggest that F optical phonons have dominant effects on the rise of current fluctuations rather than …
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Evaluations of single walled carbon nanotubes using resonance Raman spectroscopy
… found both dispersive and non-dispersive Raman bands in the range 1650-2100 cm⁻¹, and we show that the appearance and frequency vs. laser energy E[laser] behavior of these features are in agreement with predictions from double resonance Raman theory. In the case of SWNTs, these second-order …
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Modeling Error in Geographic Information Systems
… methodology into the currently popular G-band error model through the inclusion of a prior distribution on point locations. This has the advantage of working well with a small number of points, and being able to synthesize information from multiple sources. I have also calculated the …
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Chemically activated carbon using peat soil for heavy metals adsorption in industrial wastewater
… is attributed to diamond, D and graphitic, G band, respectively. FTIR spectrum analysis showed the carboxyl, ketone, aldehyde, methylene and hydroxyl groups are present on the surface of PSAC due to the activation process with H2SO4. Point of zero charge (pHpzc) of activated carbon is 5.60 …
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Chromosomal Evolution Among North American Microtine Rodents
… staining procedures were utilized: C-banding, G-banding, and silver staining. Results of the C-banding analyses indicated that autosomal heterochromatin occurs primarily at centromeric regions, although several species do have long arm interstitial or short arm heterochromatin. There …
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