Physics (PHY): Recent submissions
Now showing items 161-180 of 764
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High rydberg state recombination lines from interstellar carbon : an observational study
This thesis describes the results of an observational study of partially ionized gas in the Galaxy using low-frequency radio recombination lines of carbon, which arise due to electronic transitions at large quantum numbers ... -
Advanced wavefront sensing algorithms in astronomical adaptive optical syatems
Atmospheric turbulence limits the quality of imaging in ground-based astronomical telescopes (Hart; 2010). To obtain diffraction-limited imaging, there is a need for a technology that removes the effects of atmospheric ... -
Growth and study of certain physical properties of KTiOPO4 single crystals
The crystal growth of KTP (Potassium Titanyl Phosphate) from K?P?O?? solvent has been carried out by spontaneous crystallization as well as the top-seeded solution growth (TSSG) technique. For TSSG, a crystal growth system ... -
Phase separation and dynamics of concentrated colloids : Diffusing wave spectroscopy and brownian dynamics simulations
The purpose of this chapter is to summarize the principal results and conclusions reported in this thesis and also to point out the scope of further work. The focus of this thesis is on static and dynamic aspects of the ... -
Low temperature study of electronic transport properties of certain highly resistive crystalline and quasicrystalline alloys
A Low Temperature Study of Electronic Transport Properties of Certain Highly Resistive Crystalline and Quasicrystalline Alloys Low temperature electronic transport in metals and alloys has been and continues to be a topic ... -
Cross polarisation dynamics in solid state nuclear magnetic resonance
In this chapter, Floquet theory was employed to describe the SAP (Selective Averaging Pulse) experiment. Restriction of the CP (Cross Polarization) contact time to part of the rotor period and the application of additional ... -
Studies on phase transitions in crystals
The present Raman spectroscopic observations of the mixed crystals of ammonium and potassium sulphate in the paraelectric phase show that as the concentrations of K? ions increase in the crystal, the frequency of totally ... -
Massive spin-two bosons and the forces of nature
Chapter I begins with a general review of the four basic forces of nature, together with some of the theories that have been put forth in order to describe them. The following section, i.e., Section I.1, contains a brief ... -
Esperimental techniques and of electrical properties of critical binary liquid systems
A direct analysis of the resistance and capacitance data did not yield any unambiguous result on the value of the exponent ?. Both resistance and capacitance behave in a similar way, and the ? value seems to depend upon ... -
Raman and infrared study of vibrational and rotational relaxations
Our data on the area-ratio of the split components of the Ag Raman line in potash alum show a clear departure from the Boltzmann distribution at temperatures below 150 K. Modification of the phonon-induced transition rates ... -
Classical reltivistic particles with internal structure: a group of theoretic and differential geometric analysis
This thesis presents a systematic study of internal structures possible for a classical relativistic indecomposable particle without spatial extension. Group theoretic and differential geometric methods are used and the ... -
Studies on the preparation and semiconductor properties of clad silcon fibres
This thesis is a report of experiments made with a sample and a new approach to fabricating silicon devices in cylindrical configuration by co-drawing of two materials together at high temperatures. The co-drawing of silicon ... -
Design and construction of a pulsed high magnetic field facility and high field magnetoresistance studies in some semiconductors
Negative magnetoresistance at 77?K saturates to a value of 0.04 to 0.06 and shows anisotropic behavior. In this connection, a critical review of the experimental results and the theoretical models of negative magnetoresistance ... -
Spectroscopic Studies of Single Wall Carbon Nanotubes, Semiconducting Nanoparticles and Metallic LaB6
Raman Spectroscopy Studies on Novel Materials Raman spectroscopy is a powerful probe to study vibrational and structural properties of solids. This thesis includes spectroscopic studies of novel materials having interesting ... -
Numerical studies of three dimensional turbulence with polymer additives and two dimentional tubulence thin films
Our study contrasts clearly dissipation-reduction phenomena in homogeneous, isotropic turbulence and drag reduction in wall-bounded flows. In both these cases, the polymers increase the overall viscosity of the solution ... -
Statistical properties of three-dimensional magnetohydrodynamic turbulence
Magnetohydrodynamic (MHD) turbulence remains a challenging physical problem. Different aspects of MHD turbulence are being studied by physicists, engineers, and fluid dynamicists. In this thesis, we concentrate on studies ... -
Two dimensional vortices in the presence of a periodic potential
The major features of the phase diagram obtained from the simulation have been reproduced qualitatively in the density functional study. Of course, the DFT does not capture the continuous nature of the transition, which ... -
Study of electrical conduction in polypyrrole at various doping levels
Electrical Conduction Mechanism in Conjugated Conducting Polymer Polypyrrole In this thesis, the mechanism of electrical conduction in conjugated conducting polymer polypyrrole has been studied in high and low doping limits. ...