Physics (PHY): Recent submissions
Now showing items 161-180 of 671
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Role of inverse cascade in astrophysical turbulence
This thesis is an attempt to blend the latest observations of large-scale coherent motions-coherent structures-observed in experiments with turbulent fluids [6], with different astrophysical situations where turbulent flow ... -
A Synthesis study of the radio sky at decametre wavelengths.
This thesis describes an all-sky survey made at 34.5 MHz using the low frequency telescope situated at Gauribidanur, near Bangalore (latitude 13.36 12 N). The antenna system is made up of 1000 dipoles arranged in the ... -
Characterization, properties and dynamics of squeezed states: single mode and multimode systems
Squeezed states of the quantized electromagnetic field, as well as the squeezing phenomenon in the more general quantum mechanical context, have been topics of enormous interest recently. In addition to a very large number ... -
Wide-line and pulsed NMR instrumentation and investigations in certain Hydrazinium metal halides.
This thesis describes the wide-line and pulsed NMR instrumentation and investigations in certain hydrazinium double salts. Proton second moment and proton spin-lattice relaxation time as a function of temperature in the ... -
NMR spectroscopy of oriented systems: studies at and near magic angle sample spinning
The experiments described in this chapter are important in the context of applications mentioned in section 2.2, viz., (i) analysis of spectra of oriented molecules and (ii) use of liquid crystals for measurement of spinning ... -
Theoretical and experimental studies on open circuit voltage decay lifetime and series resistance in solar cells and other P-N junction devices
Open-Circuit Voltage Decay (OCVD) is a simple and widely used technique for determining the minority carrier lifetime (??) in p–n junction devices. In this work, theoretical expressions for both Forward Current-Induced ... -
Theoretical studies on some classical and quantum transport problems in random media
The problem of transport of charge (electrons, holes and ions) and energy (excitons) in a dynamically disordered medium is assuming increasing significance in recent times, from theoretical and experimental viewpoints. ... -
Studies on the raman spectra of crystals (PHY)
The Raman spectra of crystals have formed a very fruitful topic of study in the past and such studies, particularly on single crystals in specific orientations, have contributed in a large measure to a better understanding ... -
Magnetic braking as a solution to the angular momentum problem of ellptical galaxies
The following idea is explored in this thesis: the angular momentum problem of elliptical galaxies can be solved by invoking magnetic braking operating during the formative phases of protoelliptical galaxies. For reducing ... -
Dissipative dynamics of classical and quantum systems
The organization is as follows. In Chapter II we introduce specific systems of interest, such as RBCs, microemulsions, tethered surfaces, and monolayer films of smectic-A and smectic-B systems. In Chapter III we calculate ... -
Study of giant radio galaxies.
Within the framework of the beam model, we have deduced some basic physical parameters of the jets and hotspots associated with classical double radio sources, following a simple approach which is based on the assumptions ... -
Effect of a QSO on its host galaxy
Various arguments and observations have led to a general belief that QSO phenomenon is a form of violent activity in the nuclei of galaxies. It is natural to expect that a powerful source of high energy radiation like a ... -
Charged solution excitations and the vaccum state of.. field theories
This thesis describes some theoretical investigations on ?? field theories (i.e., theories governed by Lagrangians which are sixth-degree polynomials in ?) where ? is either a real or a complex scalar field. We work in ... -
Unified geometrical framework for gauge symmetries
The effort to discover a conceptual unity among various phenomena in the physical world is one of the major intellectual endeavours of the human mind. It is surprising that Nature apparently supports such an instinct, for, ... -
Superconducting electron pairing in the presence of a radiation field
The thesis discusses superconducting electron pairing in the presence of a radiation field. This phenomenon also called photo-induced superconductivity was studies by kumar and Sinha in 1968. It was found that microwave ... -
Topics in the statistical mechanics of extended objects
In this thesis, we study some aspects of the equilibrium and nonequilibrium statistical mechanics of physical systems with extended spatial degrees of freedom. The specific systems we model are: The Abrikosov fiux lattice ... -
Study Of the Cometary Globules in the Gum Nebula
From our analysis of the measured velocities of cometary globules (CGs), we draw the following conclusions: Kinematic Interpretation The motion of the CGs cannot be explained by a model dominated by galactic rotation, ... -
Study of radio emissions from clusters of galaxies: CD galaxies and the very steep spectrum sources
(a) An important conclusion regarding the probability of radio emission associated with the brightest galaxy in the centre of a cluster containing a VSSS (Very Steep Spectrum Source) can be drawn from the study of Table ... -
Analytic and numerical studies of neural network models of associative memory
In this thesis, we have used analytical and numerical methods to study the behaviour of neural network models for the storage, classification and associative recall of information. In Part A, we have studied a class of ... -
Thermopower probing the effect of interaction and strong correlation in twisted multilayer graphene moir´e
Two-dimensional quantum materials, especially graphene-based van der Waals heterostructures, have been at the forefront of a new era in scientific research and technological breakthroughs. From field-effect transistors to ...