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 27 for “"permittivities"”.
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Modeling the microwave frequency permittivity of thermoplastic composite materials
… in an effort to predict the microwave frequency permittivities of unidirectional-fiber-reinforced thermoplastic-matrix composite materials as a function of fiber volume fraction, fiber orientation relative to the electric field, and temperature. The permittivities of the constituent fiber and …
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A Novel Technique for the Analysis of Dielectric Waveguides
… media, and media which may have complex, dyadic permittivities and/or permeabilities.
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A direct D-bar reconstruction algorithm for complex admittivities in W2,∞(Ω) for the 2-D EIT problem
… for twice-differentiable conductivities and permittivities. In this thesis the necessary formulas to turn her proof into a direct D-bar reconstruction algorithm that solves the full nonlinear admittivity problem in 2-D are described. Reconstructions for simulated Finite Element data for …
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Competition and Coexistence of Screening Mechanisms in Ferroelectric Thin Films and Superlattices
… and superlattices. It was found that the permittivities of the substrates and paraelectric layers extended the range of thicknesses where coexistence between the screening mechanisms can be sustained. First-principles calculations of monodomain thin films and superlattices were performed …
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Dielectric elastomer composites: analytical and numerical non-convex homogenization methods and applications
… extreme behaviors ranging from unusually large permittivities and electrostriction coefficients to metamaterial-type properties featuring negative permittivities. These results suggest a promising strategy to design deformable dielectric composites --- such as electrets and dielectric elastomer …
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Numerical methods for electromagnetic wave propagation and scattering in complex media
… are studied for various rough surfaces and layer permittivities. The Finite Difference Time Domain (FDTD) method is used to study metamaterials exhibiting both negative permittivity and permeability in certain frequency bands.
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Scattering theory approach to electrodynamic Casimir forces
… subject to such forces is unstable if the permittivities of all objects are higher or lower than that of the enveloping medium; the former being the generic case for ordinary materials in vacuum.
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Studies of Passive and Active Plasmonic Core-Shell Nanoparticles and their Applications
… in size. We introduce standard models of the permittivities of the noble metals used in these CNPs, and propose corrections to them based on experimental data when their sizes are extremely small. Mie theory is the solution to plane wave scattering by spheres and we extend the solution here to …
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A dielectric study of systems exhibiting molecular association.
… between surfactant headgroups and water. Static permittivities of C[12]E[4] and Brij 30 in ternary mixtures with water and an n-alkane are attributed to normal micelles at some compositions and inverted micelles at others. Results for microemulsions of C[12]E[4] have been interpreted as …
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Design optimization of broadband rape-based reflectary antena elements for x-band applications
… The characterization results demonstrated low permittivities of 1.81, 1.63 and 1.84 for the proposed dielectric substrates, along with loss tangents of 0.053, 0.048 and 0.057 respectively. Three different types of element configurations; rectangular, double C – Slot and double U – Slot were …
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The plasmonics of a nanosphere on a mirror substrate
… modes develops, while increasingly negative permittivities give rise to surface plasmons in the film, which are sensitive to film thickness and hybridise with the particle’s plasmons, causing them to shift. Furthermore, since much of the charge in a vertically polarised particle is localised …
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Variable permittivity dielectric material loaded stepped-horn antenna
… one material, using materials with different permittivities gave extra parameters to control characteristics such as the input return loss. These study can be extended for further multi-stepped structures with variable dielectric materials.
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ULTRA-LOW K DIELECTRIC MATERIALS WITH HIGH BREAKDOWN STRENGTH AND EXCELLENT MECHANICAL PROPERTIES
… their dielectric and mechanical properties. The permittivities were measured using LCR, breakdown with PolyK Polarisation Loop & Dielectric Breakdown Test System, and mechanical properties using strain-induced elastic buckling instability measurement for mechanical property measurements …
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Dielectric and Kerr Effect Studies of Electro-Active Polymer Complexes
… through the measurement of static dielectric permittivities and Kerr constants. Experimental molar Kerr constants have been derived for the complexes and compared to theoretical values calculated using bond and group polarizabilities taken from the literature. The experimental molar Kerr …
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Theoretical and experimental studies of the field-induced phenomena in flowing suspensions
… the suspending fluid have different dielectric permittivities andlor conductivities, the particles migrate towards the regions of high or low electric field strengths depending on the sign of their polarization. This phenomenon, referred to as dielectrophoresis, has found numerous applications …
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Arbitrarily Oriented Biaxially Anisotropic Media: Wave Behavior and Microstrip Antennas
… anisotropic substrates of varying thickness, permittivities, and orientations, providing the understanding of the complex behaviors of microstrip antennas printed on biaxially anisotropic substrates.</p>
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Polymer Composite Dielectric Materials For Pulse Power Applications
… filler loadings of 20 vol%, show high dielectric permittivities and lower reduction in breakdown strength. The calculated energy density of this system is 12 J/cm3, making it suitable for pulse power applications.</p>
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Optomechanical Devices and Sensors Based on Plasmonic Metamaterial Absorbers
… between two media with different signs in real permittivities, e.g. a metal and a dielectric, stimulated by light. Plasmonics is a promising field of study, because electron oscillations inside a subwavelength space at optical frequencies simultaneously overcome the limit of diffraction in …
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Effects of wideband complex electromagnetic properties of soils on geophysical sensor performance, The
… calculate magnetic properties. The calculated permittivities are up to twice as high when measured with the coaxial probe as they are when measured with a coaxial airline fixture which will lead to incorrect estimates of GPR velocity and attenuation. To address the performance issues of metal …
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Preparation and characterization of lead lanthanum titanate thin films by metalorganic decomposition
… Pb-based perovskite family have high relative permittivities and have consequently attracted a world wide attention. Cubic Lead Lanthanum Titanate (PLT) is one of the prime candidates in this respect and its structure and properties in the thin film form were investigated in the present study, …
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