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.
Results
Showing 1 to 20 of 59 for “"Travelling wave"”.
-
Physics of Superconducting Travelling-Wave Parametric Amplifiers
Superconducting travelling-wave parametric amplifiers (TWPAs) are ultra-low-noise amplifiers that achieve amplification through the nonlinear kinetic inductance of superconductors. These devices can have near quantum-limited noise performance, and have important applications in quantum information …
-
A novel wideband gyrotron travelling wave amplifier
… a novel wideband quasioptical Gyrotron Traveling Wave Tube (gyro-TWT) amplifier and the first Vacuum Electron Device (VED) with a Photonic Band Gap (PBG) structure. The theory and experimental results from two other quasioptical gyrotron oscillator experiments are also presented. The gyro-TWT …
-
Travelling Wave Analysis of a Nonlinear Diffusion Equation
… boundary (nonlinear Stefan) problem, indicate a travelling wave behaviour that is subsequently investigated using a travelling wave analysis. Considering first a simplified linear problem, we perform a travelling wave analysis that identifies a small parameter, the natural logarithm of the …
-
Optimization of optical characteristics of travelling wave modulators
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1985.
-
Improving the design of travelling wave type sloshing absorbers
Liquid sloshing absorbers are simple structures consisting of a partially full container of liquid with a free surface. The primary objective of this thesis is to investigate the potential to improve the design of rectangular sloshing absorbers through attaching surface roughness elements …
-
Theory of optical rectification in a travelling wave structure
… is concerned with the interaction of an optical wave with a microwave in a waveguiding structure coupled by a second order nonlinearity. Emphasis is laid upon the generation of ultrashort electrical transients via optical rectification (OR) as well as cascading effects due to the interplay of OR …
-
Design and development of a linear travelling wave motor
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990.
-
Ferrofluid duct flow in alternating and travelling wave magnetic fields
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.
-
Slow-wave electrode structures for III-V semiconductor based electro-optic travelling-wave modulators
… and/or optoelectronic devices. Conventional travelling-wave electro-optic modulators fabricated using III-V semiconductor materials such as gallium arsenide and indium phosphide suffer from the problems created by the velocity-mismatch between the microwave modulating signal and the optical …
-
Beyond the tanh method-looking for explicit travelling wave solutions to partial differential equations
… focus on a general procedure for finding exact travelling wave solutions for evolution equations with polynomial nonlinearites. Mathematically, looking for travelling wave solutions is asking the question whether a given PDE has solutions invariant under a Galilean transformation; in such a …
-
Asymptotic Analysis of Perturbations to Travelling Wave Solutions of Nonlinear Advection-Reaction-Diffusion Equations of Fisher Type
… the derivation of some exact expressions for travelling wave solutions which had been obtained by previous researcher using other methods. We examine some situations where the exact travelling wave solutions are perturbed. First we perturb the initial condition and then derive approximate …
-
An investigation into high temperature superconducting flux pump technology with the circular type magnetic flux pump devices and YBaCuO films
… environment. HTS flux pump technology applies a travelling magnetic wave to fully magnetise an HTS coil, which is both efficient and economical, and has in recent years been proven feasible. However, the underlying physics of this technology are so far poorly understood. In order to study the …
-
Crossflow stability and transition experiments in a swept-wing flow
… across a single vortex track. The mean and travelling-wave disturbances are measured simultaneously. Stationary-crossflow disturbance profiles are determined by subtracting either a reference or a span-averaged velocity profile from the mean-velocity data. Mean, Stationary-crossflow, and …
-
Efficient THz lasers and broadband amplifiers based on quantum cascade gain media
… aimed for 2.060 THz atomic oxygen line. THz travelling-wave QC amplifiers are highly desired to achieve broadband amplification of THz radiation in free space. The second part of the thesis focuses on the development of 4.3 THz travelling-wave QC amplifier by monolithically integrating horn …
-
Spectral stability of solutions to Whitham-type equations with a nonlocal kernel
… a clear and reproducible outline of finding travelling wave solutions to certain nonlinear partial differential equations. This is done using a spectral cosine collocation method, and the stability of the travelling wave solutions found is then assessed using the Fourier-Floquet-Hill method. …
-
Implementation of travelling waves on lifting surface for drag reduction
… One such new approach is to introduce a travelling wave on the lifting surface, a technique inspired by the undulatory motion of fish. In order to manufacture and test such a surface, first the necessary design specifications must be determined. Using NACA0012 and NACA0018 wings at a …
-
Stability of a liquid thread and stability and nonlinear evolution of multi-layer fluid flow
… is concerned with stability and existence of waves in interfacial and free surface problems. Considered is the curtain coating problem, with specific emphasis on trilayer and bilayer flows, and the breakup of a viscous thread with a solid core. Experiments on curtain coating and sheet breakup …
-
Stability of periodic solutions to nonlinear Klein-Gordon equations
We study the stability of periodic travelling wave solutions to nonlinear Klein-Gordon equations, subject to small and localized perturbations. Using the periodic Evans function technique, we analyze the spectrum of a linearized quadratic eigenvalue pencil associated with the linearized equation, …
-
A study of certain multi-dimensional partial differential equations using Lie symmetry analysis
… method. The solutions obtained are solitary waves and non-topological solution. Conservation laws for both equations are constructed using the new conservation theorem due to Ibragimov. Lie symmetry analysis together with Kudryashov's method is used to obtained travelling wave solutions for …
-
The application of ion mobility mass spectrometry to molecules of pharmaceutical significance
… calculate collision cross-sections (CCSs) using travelling wave ion mobility spectrometry, and determine the CCS using drift-tube ion mobility spectrometry systems of analytes. The aim of the study was to identify if predictive approaches could facilitate rapid and definitive assignment of charge …
Page 1 of 3