Syamaprasad, U; Dr.Girijavallabhan, C P(Cochin University of Science And Technology, December , 1981)
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Abstract:
The thesis aims to present the results of the
experimental investigations on the electrical properties like
electrical conductivity, dielectric constant and ionic thermo~
currents in certain ammonium containing ferroelectric crystals
viz. LiNH4SO4, (NH4)2SO4 and (NH4)5H(SO4)2. Special attention
has been paid in revealing the mechanisms of electrical conduction
in the various phases of these crystals and those asso~
ciated with the different phase transitions occurring in them,
by making studies on doped, quenched and deuterated crystals.
The report on the observation of two new phase transitions in
(NH4) S O2 and of a similar one in ( NH4 ) H (2SO4 ) are included. The relaxation mechanisms of the impurity-vacancy complexes and the space charge phenomena in pure and doped crystals of LiNH4SO4 and (NH4)2SO4 and the observation of a new type of ionic thermo-current viz. Protonic Thermo-Current (PTC) in these crystals are also presented here.
Description:
Department of Physics, Cochin University of Science and Technology
Raveendran Nair, B; Dr.Joseph, Francis D(Cochin University of Science and Technology, December , 1981)
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Abstract:
Urea-formaldehyde resins find numerous
applications in adhesive, textile finishing and moulded
plastic industries. Kinetic investigations of the reactions of
urea and its related compounds with formaldehyde in
aqueous acid, alkaline and neutral media have been carried
out. A thin—layer chromatographic method was developed
for the separation and estimation of the products of these
reactions. Using this technique the various initial steps
in the reactions were analysed and the rate constants have been determined.
Description:
Department of Applied Chemistry, Cochin University of Science and Technology
Nirmala Paul; Dr.Krishna Pillai, M G(Cochin University Of Science And Technology, December 2, 1981)
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Abstract:
The thesis is a report of the attempts made to
prepare semiconducting and dielectric thin films and to
study their electrical properties. It consists of (i)
studies on the preparation and electrical characteristics
of compound semiconductor thin films of silver sulphide
and ferric hydroxide, and (ii) investigations on the electrical
and dielectric properties of plasma polymerized
thin films of para-toluidine element
Description:
Department
of Physics,Cochin University Of Science And Technology
Balakrishna Warier, K; Dr.Purushothaman, C(Cochin University of Science and Technology, January , 1982)
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Abstract:
The present thesis deals with the theoretical investigations on the effect of anisotropy on various properties of magnetically doped superconductors described by fihiba — Rusinov
model.Chapter 1 is introductory. It contains a brief account of the current status of theory of superconductivity. In’ chapter 2 we give the formulation of the problem. Chapter 2.1 gives the BCS theory. The effect of magnetic impurities in superconductors as described by A8 theory is given in chapter 2.2A and that described by SR model is discussed in chapter 2.28. Chapter 2.2c deals with Kondo effect. In chapter 2.3 the anisotropy problem is reviewed. Our calculations, results and discussions are given in chapter 3. Chapter 3.1 deals with Josephson tunnel effect. In chapter 3.2 the thermodynamic critical field H62 is described. Chtpter 3.3 deals with the density of states. The ultrasonic attenuation coefficient and ufitlear spin relaxation are given in chapter 3.4 and 3.5 respectively. In chapter 3.6 we give the upper critical field calculations and chapter 3.7 deals with the response function. The Kondo effect is given in chapter 3.8. In chapter 4 we give the sumary of our results
Description:
Department of Physics, Cochin
University of science and Technology
Velukutty, K K; Dr.Wazir, Hasan Abdi(Cochin University of Science and Technology, February 15, 1982)
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Abstract:
An attempt is made by the researcher to establish a theory of discrete functions in the complex plane. Classical analysis q-basic theory, monodiffric theory, preholomorphic theory and q-analytic theory have been utilised to develop concepts like differentiation, integration and special functions.
Description:
Department of Mathematics and Statistics, Cochin University of Science & Technology
Paul, C M; Dr.Girijavallabhan, C P(Cochin University of Science And Technology, April , 1982)
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Abstract:
The major objective of the thesis is essentially to evolve and apply certain computational procedures to evaluate the structure and properties of some simple polyatomic molecules
making use of spectroscopic data available from the literature. It must be said that though there is dwindling interest in recent times in such analyses, there exists tremendous scope
and utility for attempting such calculations as the precision and reliability of'experimental techniques in spectroscopy have increased vastly due to enormous sophistication of the instruments used for these measurements. In the present thesis an attempt is made to extract maximum amount of information regarding the geometrical structure and interatmic forces of simple molecules from the experimental data on microwave and infrared spectra of
these molecules
Description:
Department of physics, Cochin University of Science And Technology
Vasudevan, K; Dr.Nair, K G(Cochin University of Science and Technology, April 19, 1982)
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Abstract:
Antennas play an important role in determining
the characteristics of any electronic system which depends
on free space as the propagation medium. Basically, an
antenna can be considered as the connecting link between
free space and the transmitter or receiver. For radar and
navigational purposes the directional properties of an
antenna is its most basic requirement as it determines the
distribution of radiated energy. Hence the study of directional properties of antennas has got special significance
and several useful applications.
Description:
Department of Physics, Cochin University of Science and Technology
Kuriakose, V C; Dr.Babu, Joseph K(Cochin University of Science And Technology, September , 1982)
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Abstract:
The thesis deals with certain quantum field systems exhibiting spontaneous symmetry breaking and their response to temperature. These models find application in diverse branches such as particle physics, solid state physics and non~linear optics. The nature of phase transition that these systems may undergo is also investigated. The thesis contains seven chapters. The first
chapter is introductory and gives a brief account of the various phenomena associated with spontaneous symmetry breaking. The chapter closes with anote on the effect of temperature on quantum field systems. In chapter 2, the spontaneous symmetry breaking phenomena are reviewed in more detail. Chapter 3, deals with the formulation of ordinary and generalised sine-Gordon field theories on a lattice and the study of the nature of phase transition occurring in these systems. In chapter 4, the effect of temperature on these models is studied, using the effective potential method. Chapter 5 is a continuation of this study for another model, viz, the
m6 model. The nature of phase transition is also studied. Chapters 5 and 6 constitute a report of the investigations on the behaviour of coupling constants under thermal excitation D1 $4 theory, scalar electrodynamics, abelian and non-abelian gauge theories
Description:
Department of physics, Cochin University of Science And Technology
Mercy, Jacob K; Dr.Wazir, Hasan Abdi(Cochin University of Science and Technology, 1983)
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Abstract:
There is a recent trend to describe physical
phenomena without the use of infinitesimals or infinites.
This has been accomplished replacing differential calculus
by the finite difference theory. Discrete function theory
was first introduced in l94l. This theory is concerned with
a study of functions defined on a discrete set of points in
the complex plane. The theory was extensively developed for
functions defined on a Gaussian lattice. In 1972 a very
suitable lattice H: {Ci qmxO,I qnyo), X0) 0, X3) 0,
O < q < l, m, n 5 Z} was found and discrete analytic function
theory was developed. Very recently some work has been done
in discrete monodiffric function theory for functions
defined on H.
The theory of pseudoanalytic functions is a
generalisation of the theory of analytic functions. When the
generator becomes the identity, ie., (l, i) the theory of
pseudoanalytic functions reduces to the theory of analytic
functions. Theugh the theory of pseudoanalytic functions
plays an important role in analysis, no discrete theory is
available in literature. This thesis is an attempt in that
direction. A discrete pseudoanalytic theory is derived for
functions defined on H.
Description:
Department Of Mathematics and Statistics, Cochin University of Science and Technology
Joseph, K S; Dr.George, Joy(Cochin University of Science and Technology, 1983)
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Abstract:
In this thesis the preparation and properties of thin films of certain semiconducting sulphides (sulphides of tin, copper and indium) are reported. As single source evaporation does not yield satisfactory films of these compounds for a variety of reasons, reactive evaporation of the metal in a sulphur atmosphere has been used for film preparation. It was found that for each metal sulphide a stoichimetric interval of fluxes and substrate temperature exists for the formation of the compound in accordance with the analysis of Guenther. The first chapter of the thesis gives a resume of the basic principles of semiconductor physics relevant to the work reported here. In the second chapter is discussed in detail the reactive evaporation techniques like ordinary reactive evaporation, activated reactive evaporation and reactive ion plating. Third chapter deals with the experimental techniques used in this study for film preparation and characterization. In the next seven chapters is discussed the preparation and properties of the compound films studied. The last chapter gives a general theory of the formation of compound films in various deposition techniques in terms of the kinetic energy of the film forming particles. It must be mentioned here that this is of fundamental importance to thin film deposition and is virtually untouched in the literature
Description:
Department of Physics, Cochin University of Science and Technology