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 18 of 18 for “"Disordered media"”.
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Avalanches, percolation, and stochastic damage evolution in disordered media
Disordered materials are ubiquitous in nature and engineering. The physical properties of such random heterogeneous materials are strongly coupled with the strength and spatial distribution of the disorder. Disorder leads to fluctuations in material properties which become relevant for mesoscales …
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Thermal radiative properties of disordered media and deep metal gratings
Controlling thermal radiation through surface roughness, volumetric inhomogeneity and periodic micro/nanostructures has enormous applications in energy harvesting and saving, thermal management, photonics and optical sensing. The present dissertation investigates the spectral radiative properties …
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Reciprocity and Normality in the Scattering Matrix of Disordered Media
… measured scattering matrices of complex optical media via a matrix-based gradient descent procedure. Resulting phase corrections corresponded closely with classical aberration modes without heuristic parameterizations, suggesting that these modes naturally arise to restore reciprocity-induced …
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Interfaces in disordered media. Scaling growth, avalanche dynamics, and microfluidic fronts
… instance, in the problem of a fluid filling a disordered medium –where the expression <i>disordered medium</i> applies both to a macroscopic porous medium and a <i>microfluidic</i> device. The point is that all the physical forces that play a role at the advancing front, such as the random …
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A Self-Consistent Renormalized Effective Medium Theory for the Determination of Transport Coefficents of Disordered Media
Made available in DSpace on 2017-07-06T18:59:08Z (GMT). No. of bitstreams: 3 Toreja_Allen_J_MS.pdf: 97871832 bytes, checksum: 3ea9e9aee51a43a859e330e0218b2d08 (MD5) Toreja_Allen_J_MS_ABS.pdf: 579365 bytes, checksum: b921d6259dea13dc6008d71014324bac (MD5) license.txt: 4813 bytes, checksum: …
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History Induced Critical Scaling in Disordered Media and Super Diffusive Growth in Highly Advective Random Environments
… was originally developed as a simple model for disordered magnets, but has applications far beyond magnetic systems. Previous work examining history effects in models and experiments are briefly reviewed, followed by a summary of the saturation loop behavior of the RFIM. A numerical scaling …
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Localisation faible de la lumière dans un gaz d´atomes froids
… is drastically reduced with respect to classical disordered media. In the present theoretical contribution, we study the impact of the degeneracy of the atomic dipole transition on weak localisation of light. The non-scalar components of the atomic scattering operator are characteristic of the …
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Bioinspired scattering materials: light transport in anisotropic, disordered systems
The study of light propagation in disordered media has attracted the interest of many researchers for its relevance to fundamental and applied problems, ranging from imaging through turbid media to the fabrication of white paint. Scattering in a disordered system is determined by the spatial …
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Universal sound attenuation in amorphous solids at low-temperatures
"Disordered solids are known to exhibit quantitative universalities at low temperatures, the most striking of which is the ultrasonic attenuation coefficient 1/Q(ω). The established theory of tunneling two state systems (TTLS) in its original form (i.e. without extra fitting functions and …
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Real-time observation of particle interactions in matter using laser-driven accelerators
… particle interactions within ordered and disordered media is examined in various forms of SiO2. By tracking the transient opacity the recovery time of excited electrons is found to be > 150 times greater in nanostructured aerogel than in bulk fused silica, a magnitude of > 15 more than …
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Modeling single-phase flow and solute transport across scales
… (perfect mixing vs. partial mixing) in disordered media, as well as the predictive capacity of network modeling as a whole for ordered media are conducted. A mortar domain decomposition framework is additionally developed, under which efficient and accurate simulations on even larger and …
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Modification of exciton energies and dynamics for thin film optoelectronics
… wavelength lasers, photovoltaics, and sensors. Mediating photons and charges, excitons are responsible for electrical and optical properties in these energetically disordered media. To improve current technology and develop novel applications, a thorough understanding of exciton dynamics is …
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Electromagnetic Time-Reversal Imaging and Tracking Techniques for Inverse Scattering and Wireless Communications
… makes it an attractive technique for imaging in disordered media whose characteristics are not known deterministically (random media). Over the past few years, TR has been exploited in a variety of electromagnetic sensing and imaging applications such as ground penetrating radar, breast cancer …
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Spectral properties of the random conductance model
Charge and exciton transport in disordered media plays an essential role in modern technologies. Classical examples are amorphous and organic semiconductors where the disorder can give rise to localized electron states. These localized electrons effectively behave like discrete particles hopping …
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Density Fluctuations and Phase Behaviour in Non-Equilibrium Systems
… sandpiles and growth of elastic interfaces under disordered media. Using renormalisation group analysis in the Doi-Peliti formalism, a bottom-up field-theoretic approach, we characterise analytically the critical behaviour near the transition, highlighting in particular the surprisingly weak …
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Photon Statistics in Disordered Lattices
<p>Propagation of coherent waves through disordered media, whether optical, acoustic, or radio waves, results in a spatially redistributed random intensity pattern known as speckle -- a statistical phenomenon. The subject of this dissertation is the statistics of monochromatic coherent light …
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Caging and Transport in Simple Disordered Systems
… the caging and transport of a series of simple disordered systems.</p><p>We first consider the dynamics of site percolation on hypercubic lattices. Using theory and simulations, we obtain that both caging and subdiffusion scale logarithmically for dimension d ≥ d_u, the upper critical dimension …