Ajithkumar, C M; Dr.Babu, Joseph K(Cochin University of Science and Technology, 1986)
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Abstract:
In 1931 Dirac studied the motion of an electron in the field of a magnetic monopole and found that the quantization of electric charge can be explained by postulating the mere existence of a magnetic monopole. Since 1974 there has been a resurgence of interest in magnetic monopole due to the work of ‘t’ Hooft and Polyakov who independently observed that monopoles can exist as finite energy topologically stable solutions to certain spontaneously broken gauge theories. The thesis, “Studies on Magnetic Monopole Solutions of Non-abelian Gauge Theories and Related Problems”, reports a systematic investigation of classical solutions of non-abelian gauge theories with special emphasis on magnetic monopoles and dyons which possess both electric and magnetic charges. The formation of bound states of a dyon with fermions and bosons is also studied in detail.
The thesis opens with an account of a new derivation of a relationship between the magnetic charge of a dyon and the topology of the gauge fields associated with it. Although this formula has been reported earlier in the literature, the present method has two distinct advantages. In the first place, it does not depend either on the mechanism of symmetry breaking or on the nature of the residual symmetry group. Secondly, the results can be generalized to finite temperature monopoles.
Description:
Department of Physics, Cochin University of Science and Technology
Nancy, Mathew; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, June , 2011)
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Abstract:
Studies on transition metal complexes have achieved a great interest due to their versatile applications.The convenient route for synthesis,the nature of ligands and stability of metal complexes has significant contributions in their applications in medicine,biology,catalysis and photonics.The present work deals wth the synthesis and characterization of metal complexes of some tridentate acylhydrazones .Hydrazones are promising ligands in coordination chemistry with interesting binding modes and applications.The acylhydrazones chosen for the current study are capable of forming complexes in different forms through tautomerism.
Description:
Department of Applied Chemistry,Cochin University of Science and 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
Mercy, Mani P; Dr.Ramachandra Kaimal, M(Cochin University of Science And Technology, June , 1988)
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Abstract:
The nonlinear dynamics of certain important reaction systems are discussed and analysed in this thesis. The interest in the theoretical and the experimental studies of chemical reactions showing oscillatory dynamics and associated properties is increasing very rapidly. An attempt is made to study some nonlinear phenomena exhibited by the well known chemical oscillator, the BelousovZhabotinskii reaction whose mathematical properties are much in common with the properties of biological oscillators. While extremely complex, this reaction is still much simpler
than biological systems at least from the modelling point of view. A suitable model [19] for the system is analysed and the researcher has studied the limit cycle behaviour of the system, for
different values of the stoichiometric parameter f, by keeping the value of the reaction rate (k6) fixed at k6 = l. The more complicated three-variable model is stiff in nature.
Description:
Department of mathematics and statistics, Cochin University of Science And Technology
Radhakrishnan, R; Dr. Ramesh Babu, T(Cochin University of Science and Technology, July , 2008)
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Abstract:
In the present thesis we have formulated the Dalgarno-Lewis procedure
for two-and three-photon processes and an elegant alternate expressions
are derived. Starting from a brief review on various multiphoton processes
we have discussed the difficulties coming in the perturbative treatment
of multiphoton processes. A small discussion on various available methods
for studying multiphoton processes are presented in chapter 2. These
theoretical treatments mainly concentrate on the evaluation of the higher
order matrix elements coming in the perturbation theory. In chapter 3 we
have described the use of Dalgarno-Lewis procedure and its implimentation on second order matrix elements. The analytical expressions for twophoton
transition amplitude, two-photon ionization cross section, dipole
dynamic polarizability and Kramers-Heiseberg are obtained in a unified
manner. Fourth chapter is an extension of the implicit summation technique
presented in chapter 3. We have clearly mentioned the advantage of
our method, especially the analytical continuation of the relevant expressions
suited for various values of radiation frequency which is also used for
efficient numerical analysis.
A possible extension of the work is to study various multiphoton processcs
from the stark shifted first excited states of hydrogen atom. We
can also extend this procedure for studying multiphoton processes in alkali
atoms as well as Rydberg atoms. Also, instead of going for analytical expressions,
one can try a complete numerical evaluation of the higher order
matrix elements using this procedure.
Description:
Department of Physics,
Cochin University of Science and Technology
Reghunath, A T; Dr.Nampoori,V P N(Cochin University of Science And Technology, November , 1987)
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Abstract:
The central theme of the work presented in this thesis is a careful investigation of the factors influencing the attenuation of laser beam through sea water. The thesis presents a detailed report of the work done by the author on the attenuation studies in sea water and on laser propagation through a turbulent medium. The thesis contains six chapters which are more or less self-contained with separate abstracts and references. The first chapter is divided into two parts. The first part introduces the subject of laser propagation through sea water. It includes a brief
description of optical properties of sea water followed by a review of the earlier works on attenuation studies in water. The second part gives the theoretical background of the problem
of laser propagation through a turbulent medium.
Description:
Department of physics, Cochin University of Science And Technology
Rajesh, K M; Dr.Sugunan, S(Cochin University of Science and Technology, May , 2011)
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Abstract:
The present work aims to prepare visible light responsive anion doped titania via sol-gel precipitation method.The prepared catalysts were characterized by various techniques.The photocatalytic abilities of the prepared catalysts were measured by the degradation of dyes,pesticides,hydrogen production through water splitting reaction and antibacterial study.We also compared the activities of prepared catalysts with pure titania prepared in the laboratory and one of the commercial anatase titania samples.
Description:
Dept.of Applied Chemistry,Cochin University of Science and Technology
Manzur Ali, P P; Dr.Elyas, K K(Cochin University of Science and Technology, December 19, 2012)
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Abstract:
Protease inhibitors are found abundantly in numerous plants, animals and microorganisms, owing their significance to their application in the study of enzyme structures, reaction mechanisms and also their utilization in pharmacology and agriculture. They are (synthetic/natural) substances that act directly on
proteases to lower the catalytic rate. Although most of these inhibitory proteins are directed against serine proteases, some target cysteine, aspartyl or metalloproteases (Bode and Huber, 1992). Protease inhibitors are essential for regulating the activity of their corresponding proteases and play key regulatory roles in many biological processes. Applications of protease inhibitors are intimately connected to the proteases they inhibit; an overview of proteases with the modes of regulation of their proteolytic activity is discussed
Description:
Department of Biotechnology, Cochin University of Science and Technology
Aloysius, R P; Dr.Syamaprasad,U(Cochin University Of Science And Technology, December 30, 2002)
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Abstract:
The application vistas of superconductors have widened very
much since the discovery of high TC superconductors (HTS) as many of the
applications can be realised at 77 K rather than going down to 4.2 K, the
liquid He temperature. One such application is the HTS current lead which is
used to connect a superconducting system with a room temperature power
source. Minimising heat leak to the cryogenic environment is the main
advantage of introducing current leads into superconducting systems. The
properties of HTSS likes zero resistance (avoiding joule heating) and very
low thermal conductivity (minimized conductive heat transfer) make them
ideal candidates to be used as current leads. There are two forms of HTS
current leads. (i) bulk form (tube or rod) prepared either from YBCO or
BSCCO and (ii) tape form prepared from Bi-2223 multifilamentary tapes.
The tape form of current leads has many advantages with respect to the
mechanical and thermal stability related criteria. Crucial information on
various aspects of HTS current lead development are not available in the
literature as those are kept proprietary by various companies around the
world. The present work has been undertaken to tailor the properties of
multifilamentary tapes for the current lead application and to optimise the
processing parameters of the same for enhanced critical current density and
field tolerance. Also it is the aim of the present investigation is to prepare
prototype current leads engineered for operation in conduction cooled mode
and test them for operational stability
Description:
Council Of Scientific And Industrial Research [Csir]
Regional Research Laboratory
Trivandrum
Subramaniyan, S; Dr. Prema, P(Regional Research Laboratory, February , 2000)
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Abstract:
Xylanases with hydrolytic activity on xylan, one of the hemicellulosic
materials present in plant cell walls, have been identified long back and the
applicability of this enzyme is constantly growing. All these applications
especially the pulp and paper industries require novel enzymes. There has
been lot of documentation on microbial xylanases, however, none meeting all
the required characteristics. The characters being sought are: higher
production, higher pH and temperature optima, good stabilities under these
conditions and finally the low associated cellulase and protease production.
The present study analyses various facets of xylanase biotechnology giving
emphasis on bacterial xylanases. Fungal xylanases are having problems like
low pH values for both enzyme activity and growth. Moreover, the associated
production of cellulases at significant levels make fungal xylanases less
suitable for application in paper and pulp industries.Bacillus SSP-34 selected from 200 isolates was clearly having xylan
catabolizing nature distinct from earlier reports. The stabilities at higher
temperatures and pH values along with the optimum conditions for pH and
temperature is rendering Bacillus SSP-34 xylanase more suitable than many of
the previous reports for application in pulp and paper industries.Bacillus SSP-34 is an alkalophilic thertmotolerant bacteria which
under optimal cultural conditions as mentioned earlier, can produce 2.5 times
more xylanase than the basal medium.The 0.5% xylan concentration in the medium was found to the best
carbon source resulting in 366 IU/ml of xylanase activity. This induction was
subjected to catabolite repression by glucose. Xylose was a good inducer for
xylanase production. The combination of yeast extract and peptone selected
from several nitrogen sources resulted in the highest enzyme production
(379+-0.2 IU/ml) at the optimum final concentration of 0.5%. All the cultural
and nutritional parameters were compiled and comparative study showed that the modified medium resulted in xylanase activity of 506 IU/ml, 5 folds higher than the basal medium.The novel combination of purification techniques like ultrafiltraton,
ammonium sulphate fractionation, DEAE Sepharose anion exchange
chromatography, CM Sephadex cation exchange chromatography and Gel
permeation chromatography resulted in the purified xylanase having a specific
activity of 1723 U/mg protein with 33.3% yield. The enzyme was having a
molecular weight of 20-22 kDa. The Km of the purified xylanase was 6.5 mg
of oat spelts xylan per ml and Vmax 1233 µ mol/min/mg protein.Bacillus SSP-34 xylanase resulted in the ISO brightness increase from
41.1% to 48.5%. The hydrolytic nature of the xylanase was in the endo-form.Thus the organism Bacillus SSP-34 was having interesting
biotechnological and physiological aspects. The SSP-34 xylanase having
desired characters seems to be suited for application in paper and pulp
industries.