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 28 for “"Phase Fluctuations"”.
-
Spatial correlation of lipid phase fluctuations in model membranes studied with two-photon fluorescence microscopy
The temporal dynamics of lipid phase fluctuations and the spatial organization of model lipid membranes was studied using Two-photon excitation fluorescence microscopy. Lipid membranes of different composition were reconstituted in Giant Unilamellar Vesicles (GUVs) and labeled with the environment …
-
Phenomenological phase-fluctuation model for the underdoped cuprates
In this thesis, a phenomenological phase-fluctuation model for the pseudogap regime of the underdoped cuprates was discussed. The key idea of the phase-fluctuation scenario in the high-T_c superconductors is the notion that the pseudogap observed in a wide variety of experiments arises from phase …
-
High contrast interferometry and finite temperature coherence of Bose-Einstein condensates
… are of great interest, in particular phase coherence, which has played an important role in fundamental research involving BEC interferometry. When subject to high cloud aspect ratios, BECs become elongated and exhibited phase fluctuations, which can have a dramatic affect on the …
-
Quantum coherence and magnetism in bosonic and fermionic gases of ultracold atoms
… interactions provides strong evidence for a phase transition to a ferromagnetic state. Our observations imply that itinerant ferromagnetism of delocalized fermions is possible without lattice and band structure, and our data validate the most basic model for ferromagnetism introduced by …
-
The effect of internal waves on long range acoustic propagation in the ocean
… using wave techniques. Refractive index fluctuations due to the vertical displacements of the internal waves create an inhomogeneous waveguide. The analysis uses weak scattering theory based upon the Rytov perturbation technique. It is found that the internal wave field acts as a …
-
Simulation of High Frequency Waves Reflected From a Turbulent Ionosphere for Spread Spectrum Systems
… wave field. The computation of the random fluctuations of the received wave field is performed by using the phase screen-diffraction layer method. This scheme simulates the propagation of an HF wave in the turbulent ionosphere. Based on the forward-scatter approximation, the scheme computes …
-
Superfluid Density Measurements of High-Temperature Superconducting Films
… the Tc, the superfluid density exhibits critical phase fluctuations described by an XY model. These phase fluctuations are compared to a model of the pseudogap described by preformed pairs. In contrast to previous reports on YBCO films, we find that the phase transition in a YBCO film is described …
-
An Investigation of the Variability of Tides in the Upper Mesosphere (Meteor Radar)
… waves. The semidiurnal tide also exhibits phase fluctuations indicating the possible presence of a transient S(,2,3) mode.
-
Diffusion of titanium and niobium in b.c.c. Ti-Nb alloys
… heat treated by annealing above the a-B phase transition temperature and then either cooling slowly to room temperature or quenching. The room temperature crystal morphology was then examined using x-ray diffraction. Alloy concentrations were chosen both to suppress the B-a transition and …
-
Nonlinear dissipative dynamics of optomechanical and laser arrays
… self-oscillator enables us to take quantum fluctuations into account using the quantum master equation formalism. We show that the generation of synthetic electric fields is robust against fluctuations and unidirectional light transport can be achieved also in the quantum regime. In the …
-
Spectral characteristics of low-frequency variability in compact extragalactic radio sources
… for the spectral characteristics of the observed fluctuations. Plane waves from extragalactic radio sources propagating through the interstellar medium, a medium with fluctuations of the refractive index due to electron density irregularities, emerge from that medium corrugated. Since fluctuations …
-
Comparative Study of Forward and Diffusely Scattered Light in a Coherently Prepared Ultracold Rubidium Gas
… these measurements the two laser fields are not phase-locked, so ground state coherence will be affected by the lasers' phase fluctuations. Observation of the forward and diffusely scattered light were made for different conditions of probe pulse length, control field intensity, and probe field …
-
System identification and control of magnetic bearing systems
… were designed to deal with the magnitude and phase fluctuations around the two dominant resonant frequencies. The designed conventional controller and notch filters have been implemented using MATLAB, SIMULINK and dSPACE DS1102 digital signal processing (DSP) card. Both the step response and …
-
Gas phase hydrodynamics inside a circulating fluidized bed
… been indirect measurements of gas velocities and fluctuations. The gas phase is important as the motion of the particles is controlled by the gas. Accurate simulations of CFB's are not possible without accurate information on the gas phase. Instrumentation was developed for use in measuring gas …
-
Ionospheric Scintillation Prediction, Modeling, and Observation Techniques for the August 2017 Solar Eclipse
… Ionospheric scintillation is rapid amplitude and phase fluctuations of signals passing through the ionosphere caused by electron density irregularities in the ionosphere. At mid-latitudes, scintillation is not as common of an occurrence as it is in equatorial or high-altitude regions. One of the …
-
Resistance in Superconducting Epitaxial Niobium Nanowires
The thermally activated phase slip description of resistance in one-dimensional superconducting wires is unable to explain additional resistance observed in extremely narrow nanowires well below the critical temperature. However, attributing this additional resistance to quantum phase slips has …
-
Phase stabilization of laser beams in a cold atom accelerometer
… limited by the stability of the relative laser phase of the two interrogation laser beams, which is adversely affected by vibrations and temperature fluctuations of the interrogation beam optics. Without an independent measurement, the cold atom interferometer cannot distinguish platform …
-
Semiclassical approaches to Quantal Andreev Billiards and Other Topics in Inhomogeneous Superconductivity
… the pseudogap regime, but with pair-potential phase-fluctuations that destroy long-range ordering, then the low-energy states near extended impurities in the superconducting state should persist as resonances in the pseudogap regime. Thus, such states can serve as a probe of d-wave correlations …
-
Spectral-domain optical coherence phase microscopy for quantitative biological studies
Conventional phase-contrast and differential interference contrast microscopy produce high contrast images of transparent specimens such as cells. However, they do not provide quantitative information or do not have enough sensitivity to detect nanometerlevel structural alterations. We have …
-
Contemporary Ionospheric Scintillation Studies: Statistics, 2D Analytical and 3D Numerical Inversion
… irregularities can lead to random amplitude and phase fluctuations of the signal, otherwise known as scintillation, which can severely impact the performance of Global Navigation Satellite System (GNSS) and communication systems. Research into high latitude scintillation, through statistical …
Page 1 of 2