Jes,Paul; Dr. Paulose, C S(Cochin University of Science and Technology, February , 2011)
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Abstract:
In the present study, the effects of 5-HT, GABA and Bone Marrow Cells
infused intranigrally to substantia nigra individually and in combinations on
unilateral rotenone infused Parkinsonism induced rats. Scatchard analysis of DA,
DA D1 and D2 receptors in the corpus striatum, cerebral cortex, cerebellum, brain
stem and hippocampus showed a significant increase in the Brain regions of
rotenone infused rat compared to control. Real Time PCR amplification of DA D1,
D2, Bax and ubiquitin carboxy-terminal hydrolase were up regulated in the brain
regions of rotenone infused rats compared to control. Gene expression studies of
-Synuclien, cGMP and Cyclic AMP response element-binding protein showed a
significant down regulation in Rotenone infused rats compared to control.
Behavioural studies were carried out to confirm the biochemical and molecular
studies.Our study demonstrated that BMC administration alone cannot reverse the
above said molecular changes occurring in PD rat. 5-HT and GABA acting
through their specific receptors in combination with bone marrow cells play a
crucial role in the functional recovery of PD rats. 5-HT, GABA and Bone marrow
cells treated PD rats showed significant reversal to control in DA receptor binding
and gene expression. 5-HT and GABA have co-mitogenic property. Proliferation
and differentiation of cells re-establishing the connections in Parkinson's disease facilitates the functional recovery. Thus, it is evident that 5-HT and GABA along
with BMC to rotenone infused rats renders protection against oxidative, related
motor and cognitive deficits which makes them clinically significant for cellbased
therapy. The BMC transformed to neurons when co-transplanted
with 5-HT and GABA which was confirmed with PKH2GL and nestin.
These newly formed neurons have functional significance in the therapeutic
recovery of Parkinson’s disease.
Description:
Department
of Biotechnology, Cochin University of Science and Technology
Leena,P; Dr.Babu, C A(Department of Atmospheric Science, 2000)
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Abstract:
The objective of the study is to examine the dynamic and thermodynamic structure and the variations that occur in the surface layer during the pre-monsoon, onset and post-monsoon periods over the Indian region. The variations caused during the occurrence of micro and mesoscale systems, structure and variation in the marine boundary layer over the Indian region is also investigated. The drag coefficient computed indirectly also shows variation during various seasons. The thermodynamic structure of the atmosphere shows variation during the various seasons. The onset monsoon causes lowering of the Lifting Condensation Levels. The outcome of the study is expected to provide a better understanding of the structure and variations in the boundary layer over India, which is useful for many applications especially for numerical modeling studies.
Hamza, Varikoden; Dr.Babu, C A(Department of Atmospheric Science, May , 2006)
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Abstract:
Atmospheric Boundary layer (ABL) is the layer just above the earth surface and is influenced by the surface forcing within a short period of an hour or less. In this thesis, characteristics of the boundary layer over ocean, coastal and inland areas of the atmosphere, especially over the monsoon regime are thoroughly studied. The study of the coastal zone is important due to its high vulnerability mainly due to sea breeze circulation and associated changes in the atmospheric boundary layer. The major scientific problems addressed in this thesis are diurnal and seasonal variation of coastal meteorological properties, the characteristic difference in the ABL during active and weak monsoons, features of ABL over marine environment and the variation of the boundary layer structure over an inland station.
The thesis describes the various features in the ABL associated with the active and weak monsoons and, the surface boundary layer properties associated with the active and weak epochs. The study provides knowledge on MABL and can be used as the estimated values of boundary layer parameters over the marine atmosphere and to know the values and variabilities of the ABL parameters such as surface wind, surface friction, drag coefficient, wind stress and wind stress curl.
Rajeev, Kumar K; Dr.Sathianandan, K(Cochin University of Science and Technology, June 20, 1989)
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Abstract:
A brief account of the several methods used for the production of thin films is presented in this Chapter. The discussions stress on the important methods used for the fabrication of a-si:H thin films. This review' also reveals ‘that almost all the general methods, like vacuum evaporation, sputtering,
glow discharge and even chemical methods are currently employed for the production of a-Si:H thin films. Each method has its own advantages and disadvantages. However, certain methods are generally preferred. Subsequently a detailed account of the method used here for the preparation of amorphous silicon thin films and their hydrogenation is presented. The metal chamber used for the electrical and dielectric measurements is also described. A brief mention is made-on the electrode
structure, film area and film geometry.
Description:
Division of Thin Film, Department
of Physics, Cochin University of Science and Technology
Navil Kumar, R; Dr.Girijavallabhan,C P(Cochin University Of Science And Technology, June 28, 1989)
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Abstract:
In the present thesis a series of exhaustive
investigations have been carried out on a number of crystalline
samples with special reference tx> the jphase transitions
exhibited by them. These include single crystals
of pure, doped or deuterated specimens of certain ammonium
containing crystals viz., (NH )34H(SO4)2, (NH4)2HPO4,
(NH4)2Cr2O7 znui NH4H2PO4. ac/dc electrical conductivity,
dielectric constant, ionic thermocurrent as wwifil as photoacoustic
measurements have been carried out on most of
them over a wide range of temperature. In addition investigations
have been carried out in pure and doped single
crystals of NaClO3 and NaNO3 using ionic thermocurrent
measurements and these are presented here. Special attention
has been paid to reveal the mechanism of electrical conduction
in various phases of "these crystals and to evaluate
the different parameters involved in the conduction as well
as phase transition process.
The thesis contains ten chapters ‘
Description:
Department of Physics, Cochin
University of Science and Technology
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
Abraham,P K; Dr.Sathianandan, K(Cochin University of Science and Technology, July , 1989)
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Abstract:
This thesis Entitled Electrical switching studies on the thin flims of polyfuran and polyacrylonitrile prepared by plasma polymerisation and vacuum evaporated amorphous silicon.A general introduction to the switching and allied phenomena is presented. Subsequently, developments of switching in thin films are described. The Mott transition is qualitatively presented. The working of a switching transitor is outlined and compared to the switching observed in thin films. Characteristic parameters of switching such as threshold voltage, time response to a, voltage pulse, and delay time are described. The various switching configurations commonly used are discussed. The mechanisms used to explain the switching behaviour like thermal, electrothermal and purely electronic are reviewed. Finally the scope, feasibility and the importance of polymer thin films in switching are highlighted.
Description:
Department of Physics, Division of Thin Film, Cochin University of Science and Tecnology
Harikumar,P S; Dr.Sivasankara Pillai, V N(Cochin University of Science and Technology, 1990)
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Abstract:
The primary aim of these investigations was to probe the elecnuchemical
and material science aspects of some selected metal phthalocyanines(MPcs).Metal phthalocyanines are characterised by a unique planar molecular structure. As a single
class of compounds they have been the subject of ever increasing number of physicochemical and
technological investigations. During the last two decades the literature on these compounds was
flooded by an outpour of original publications and patents. Almost every branch of materials science
has benefited by their application-swface coating, printing, electrophotography, photoelectrochemistry,
electronics and medicine to name a few.The present study was confined to the electrical and electrochemical properties of cobalt,
nickel, zinc. iron and copper phthalocyanines. The use of soluble Pes as corrosion inhibitor for
aluminium was also investigated.In the introductory section of the thesis, the work done so far on MPcs is reviewed. In this
review emphasis is given to their general methods of synthesis and the physicochemical properties.In phthalocyanine chemistry one of the formidable tasks is the isolation of singular species.
In the second chapter the methods of synthesis and purification are presented with necessary
experimental details.The studies on plasma modified films of CoPe, FePc, ZnPc. NiPc and CuPc are also presented.Modification of electron transfer process by such films for reversible redox systems
is taken as the criterion to establish enhanced electrocatalytic activity.Metal phthalocyanines are p- type semiconductors and the conductivity is enhanced by
doping with iodine. The effect of doping on the activation energy of the conduction process is
evaluated by measuring the temperature dependent variation of conductivity. Effect of thennal
treatment on iodine doped CoPc is investigated by DSC,magnetic susceptibility, IR, ESR and
electronic spectra. The elecnucatalytic activity of such doped materials was probed by cyclic
voltammetry.The electron transfer mediation characteristics of MPc films depend on the film thickness.
The influence of reducing the effective thickness of the MPc film by dispersing it into a conductive
polymeric matrix was investigated. Tetrasulphonated cobalt phthalocyanine (CoTSP) was
electrostatically immobilised into polyaniline and poly(o-toluidine) under varied conditions.The studies on corrosion inhibition of aluminium by CoTSP and CuTSP and By virtue of their anionic character they are soluble in water and are strongly adsorbed on aluminium.
Hence they can act as corrosion inhibitors. CoTSP is also known to catalyze the reduction of
dioxygen.This reaction can accelerate the anodic dissolution of metal as a complementary reaction.
The influence of these conflicting properties of CoTSP on the corrosion of aluminium was studied
and compared with those of CuTSP.In the course of these investigations a number of gadgets like cell for measuring the electrical
conductivity of solids under non-isothermal conditions, low power rf oscillator and a rotating disc
electrode were fabricated.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Jayan,Thomas; Sivasankara Pillai,V N(Department of Applied Chemistry,Faculty of Science, 1995)
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Abstract:
The thesis deals with the preparation of chemical, optical, thermal and electrical characterization of five compounds, namely metal free naphthalocyanine, vanadyl napthalocyanine, zinc naphlocyanine, europium dinaphthalocyanine, and europium diphthalocyanine in the pristine and iodine-doped forms. Two important technological properties of these compounds have been investigated. The electrical properties are important in applications sensors and semiconductor lasers. Opto-thermal properties assume significance for optical imaging and data recording. The electrical properties were investigated by dc and ac techniques. This work has revealed some novel information on the conduction mechanism in five macrocyclic compounds and their iodine-doped forms. Also useful data on the thermal diffusivity of the target compounds have been obtained by optical techniques.
Narayanan, P; Dr.Sivasankara Pillai, V N(Cochin University of Science and Technology, September , 1992)
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Abstract:
Metal phthalocyanines have some unique optical
properties which are exploited for dyeing fibers and films
used in applicationslike dye lasing and optical information
storage. Aggregation of dye molecules modifies their
absorption and emission spectra with concomitant
degradation in their energy transfer characteristics. MPcs
as such have poor processability and are seldom used in
solid matrices. The finest energy transfer characteristics
are shown by the monomers of metal phthalocyanines. In the
third chapter of this thesis the studies on two series of
metal phthalocyanines are repoted
Description:
Department of Applied Chemistry, Cochin University of Science And Technology
Anoop, N A; Dr. Sreekumar, K(Cochin University Of Science And Technology, September 12, 2013)
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Abstract:
High energy materials are essential ingredients in both rocket and explosive
formulations. These can be vulnerable due to maltreatment. During gulf war, several
catastrophic accidents have been reported from their own payload munitions. The role of
energetic binders here was to wrap the explosive formulations to convert it into insensitive
munitions. With the aid of energetic binders, the explosive charges are not only protected
from tragic accidents due to fire, bullet impact, adjacent detonation, unplanned
transportation, but also form total energy output presumption.
The use of energetic binders in rocket propellants and explosive charges has been
increased after the Second World War. Inert binders in combination with energetic
materials, performed well as binders but they diluted the final formulation. Obviously the
total energy output was reduced. Currently, the research in the field of energetic polymers is
an emerging area, since it plays crucial role in insensitive munitions.
The present work emphasises on the synthesis and characterization of oxetanes,
oxiranes and polyphosphazene based energetic polymers. The thesis is structured into six
chapters. First part of chapter 1 deals with brief history of energetic polymers. The second
part describes a brief literature survey of energetic polymers based on oxetanes and oxiranes.
Third and fourth parts deal with energetic plasticizers and energetic polyphosphazenes.
Finally, the fifth part deals with the various characterization techniques adopted for the
current study and sixth part includes objectives of the present work.
Description:
Department Of Applied Chemistry,
Cochin University Of Science And Technology
Meril, Mathew; Dr.Sudha Kartha,C(Cochin University of Science & Technology, January , 2009)
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Abstract:
In the present work, structural, optical and electrical properties of indium
sulfide are tuned by specific and controlled doping. Silver, tin, copper and chlorine
were used as the doping elements. In2S3 thin films for the present study were prepared
using a simple and low cost “Chemical Spray Pyrolysis (CSP)” technique. This
technique is adaptable for large-area deposition of thin films in any required shape and
facilitates easiness of doping and/or variation of atomic ratio. It involves spraying a
solution, usually aqueous, containing soluble salts of the constituents of the desired
compound onto a heated substrate. Doping process was optimized for different doping
concentrations. On optimizing doping conditions, we tuned the structural, optical and
electrical properties of indium sulfide thin films making them perform as an ideal
buffer layer.
Description:
Department of Physics,
Cochin University of Science and Technology