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 38 for “"Nonlinear phenomena"”.
-
Strongly Nonlinear Phenomena and Singularities in Optical, Hydrodynamic and Biological Systems
… formation is an inherent feature of equations in nonlinear physics, in many situations such as in self-focusing of light nonlinearity is essential part of the model and physical events cannot be captured by linearized equations. There are nonlinear systems, such as $1$D NLSE where singularities in …
-
Orders of Magnitude Enhancement of Optical Nonlinear Phenomena in Subwavelength Metal-Dielectric Gratings
Nonlinear optical materials give rise to a multitude of phenomena that have important applications in technology and science. Due to small nonlinearities in naturally occurring materials, large optical fields are necessary to realize measurable nonlinear phenomena. The necessity of high intensity …
-
Advantageous Utilization of Nonlinear Phenomena in Micro-Structures and Macro-Structures: Applications to Micro-Resonators and Atomic Force Microscopy
Within this work, the nonlinear oscillations of various beam-like structures are studied. Methods are developed to analyze systems of this type to better understand their behavior in order to utilize the nonlinear phenomena associated with them and to provide insights for device development. The …
-
Enhancing Nonlinear Ultrasonic Methods for Laboratory and Clinical Applications
… addresses the underlying physics associated with nonlinear ultrasonic field propagation, measurements of the nonlinear properties of materials, and mechanisms contributing to the observed systematic variation of backscattered ultrasonic energy from the heart over the heart cycle. Studies were …
-
Numerical Simulation of Reinforced Concrete Subjected to Multiaxial Stress Conditions
… This composite material demonstrates a highly nonlinear behavior caused by cracking, crushing, aggregate interlock, bond slip, dowel action, shrinkage and creep. Because the reinforced concrete involves so many nonlinear phenomena interacting with one another, the formulation of a "complete" …
-
Nonlinear Dynamics of Annular and Circular Plates Under Thermal and Electrical Loadings
The nonlinear static and dynamic response of circular and annular plates under electrostatic, thermal, and combined loading is investigated. The main motivation for the study of these phenomena is providing fundamental insights into the mechanics of micro-electro-mechanical-systems (MEMS). MEMS …
-
Describing and forecasting patient census: Comparing linear and nonlinear analysis results
… with the environment. As such, they are nonlinear phenomena. Chaos theory offers methods for analyzing and modeling nonlinear phenomena. Scientists applying chaos theory to management agree that nonlinear analysis provides new information, they do not agree, however, on what statistical …
-
Spacetime Meshing for Discontinuous Galerkin Methods
… algorithm suitable for efficient solution of nonlinear phenomena using spacetime discontinuous Galerkin finite element methods. Given a triangulated d-dimensional Euclidean space domain M (a simplicial complex) corresponding to time t = 0 and initial conditions of the underlying hyperbolic …
-
Synchronization in Coupled Opto-thermal Silicon MEMS Limit Cycle Oscillators
Micro- and nano-scale oscillators exhibit nonlinear phenomena such as limit cycle oscillations, self-synchronization, and frequency entrainment to an external drive. In this work, we chart the behavior of silicon MEMS oscillators that are nominally 40 µm long and 205 nm thick, mechanically coupled, …
-
Nonlinear interactions of internal gravity waves in a continuously stratified fluid
… wavefield being sufficiently energetic for nonlinear effects to play an important role in the internal wave dynamics. Numerical studies of oceanic internal waves (such as Broutman & Young, 1986) have suggested that under the right conditions a weak internal gravity wave can be strongly …
-
Nonlinear interactions of internal gravity waves in a continuously stratified fluid
… wavefield being sufficiently energetic for nonlinear effects to play an important role in the internal wave dynamics. Numerical studies of oceanic internal waves (such as Broutman & Young, 1986) have suggested that under the right conditions a weak internal gravity wave can be strongly …
-
High field terahertz radiation : conduits to synchronized hyper spectral systems
After the first experiments of nonlinear phenomena in optics, the development of the mode-locked laser has led to rapid proliferation of the study of nonlinear frequency conversion techniques-enabling the conversion of light from the infra-red, all the way to the soft X-Ray region. However, …
-
Analysis of a Nonlinear vibration absorber for vibration control in a hand-held impact machine
… The novelty of this work lies in the use of nonlinear mass– spring–damper models to describe tool dynamics, coupled with lumped-mass models of the hand–arm system. Traditionally, linear models have been employed for such evaluations; by contrast, this study introduces nonlinear modeling to …
-
Nonlinear resonances in systems having many degrees of freedom
… combination and internal resonances in a weakly nonlinear system having many degrees of freedom. The system has cubic nonlinearities, modal linear viscous damping and is subject to harmonic excitations. The method of multiple scales, a perturbation technique, is used to develop a unified method …
-
The recategorization of "chaos": a case study of language change and theory change
… of measurement problems associated with certain nonlinear phenomena, the observability of chaotic systems is severely limited. In such cases, ongoing processes of language change may play a greater role in shaping scientific theories than in cases in which the phenomena are more easily observed. …
-
Nonlinear analysis and control of chemical reactors
This thesis carries out a detailed study of a nonlinear spectral theory that is useful for modeling and controlling chemical reactors. The motivation for this work originates from a few reports which have demonstrated in the past that the nonlinear spectral method offers a useful mathematical …
-
Nonlinear behaviour of pulsating white dwarfs
… approach, I have investigated the nonlinear properties of the pulsations of two white dwarfs, namely DA G29-38 and DB GD358. The data at my disposal comprised numerous single- and multi-sites time series photometric campaigns, including light curves from four Whole Earth Telescope …
-
Characterising nonlinear waveguides by scanning near-field optical microscopy
… been applied to investigate the dispersion and nonlinear phenomena in a multimode Ta2O5 rectangular waveguide. Unlike the conventional approach of observing only the output spectra, the SNOM technique can collect the localised spectra from the evanescent field at various locations of the …
-
Participatory sensing fuel-efficient navigation system GreenGPS
… dimensional spaces to develop models of complex nonlinear phenomena, how to build a general but personalizable fuel-saving navigation system, how to infer the information on location and type of traffic regulators with low effort and expense, and how to insure reliability of the modeling …
Page 1 of 2