Palson,T I; Dr.Joy, George(Cochin University Of Science And Technology, February 16, 1987)
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Abstract:
The work reported in this thesis is the preparation,
and the structural, electrical and optical properties
of reactively evaporated lead sulphide and tin telluride
thin films. The three temperature method had been used
for the preparation of these semiconductor thin films.
In this preparation technique constituent elements are
evaporated from separate sources with the substrate kept
at a particular temperature. when one of the constituent
element is a gas near room temperature, the method is
often called reactive evaporation. It has been found for
many materials that a stoichiometric interval exists with
a limited range of flux and substrate temperature. Usually
this technique is used for the preparation of thin films of
high melting point compounds or of materials which decompose
during evaporation. Tin telluride and lead sulphide are
neither high melting point materials nor do they decompose
on melting. But even than reactive evaporation offers the
possibility of changing the ratios of the flux of the constituent
elements within a wide range and studying its
effect on the properties of the films
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
Dhannia, T; Dr.Jayalekshmi, S(Cochin University of Science and Technology, January 30, 2012)
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Abstract:
This thesis Entitled INVESTIGATIONS ON THE STRUCTURAL, OPTICAL AND MAGNETIC PROPERTIES OF NANOSTRUCTURED CERIUM OXIDE IN PURE AND DOPED FORMS AND ITS POLYMER NANOCOMPOSITES.Synthesis and processing of nanomatelials and nanostmctures are the essential aspects of nanotechnology. Studies on new physical properties and
applications of nanomaterials and nanostructures are possible only when nanostructured materials are made available with desired size, morphology,crystal structure and chemical composition.Recently, several methods have been developed to prepare pure and doped CeO2 powder, including wet chemical synthesis, thermal hydrolysis, flux method, hydrothermal synthesis, gas condensation method, microwave technique etc. In all these, some special reaction conditions, such as high temperature, high pressure, capping agents, expensive or toxic solvents etc. have been involved.Another hi gh-li ght of the present work is room temperature ferromagnetism in cerium oxdie thin films deposited by spray pyrolysis technique.The observation of self trapped exciton mediated PL in ceria nanocrystals is another important outcome of the present study. STE mediated mechanism has been proposed for CeO2 nanocrystals based on the dependence of PL intensity on the annealing temperature. It would be interesting to extent these investigations to the doped forms of cerium oxide and cerium oxide thin
films to get deeper Insight into STE mechanism.Due to time constraints detailed investigations could not be canied out on the preparation and properties of free standing films of polymer/ceria
nanocomposites. It has been observed that good quality free standing films of PVDF/ceria, PS/C61‘l8, PMMA/ceria can be obtained using solution casting technique. These polymer nanocomposite films show high dielectric constant around 20 and offer prospects of applications as gate electrodes in metal-oxide semiconductor devices.
Description:
Division for Research in Advanced Materials,
Department of Physics,
Cochin University of Science and Technology
Dhannia, T; Dr. S. Jayalekshmi(Cochin University of Science and Technology, January 30, 2012)
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Abstract:
In recent years, nanoscience and nanotechnology has emerged as one of
the most important and exciting frontier areas of research interest in almost all
fields of science and technology. This technology provides the path of many
breakthrough changes in the near future in many areas of advanced technological
applications. Nanotechnology is an interdisciplinary area of research and
development. The advent of nanotechnology in the modern times and the
beginning of its systematic study can be thought of to have begun with a lecture by
the famous physicist Richard Feynman. In 1960 he presented a visionary and
prophetic lecture at the meeting of the American Physical Society entitled “there is
plenty of room at the bottom” where he speculated on the possibility and potential of
nanosized materials.
Synthesis of nanomaterials and nanostructures are the essential aspects of
nanotechnology. Studies on new physical properties and applications of
nanomaterials are possible only when materials are made available with desired
size, morphology, crystal structure and chemical composition. Cerium oxide (ceria)
is one of the important functional materials with high mechanical strength, thermal
stability, excellent optical properties, appreciable oxygen ion conductivity and
oxygen storage capacity. Ceria finds a variety of applications in mechanical
polishing of microelectronic devices, as catalysts for three-way automatic exhaust
systems and as additives in ceramics and phosphors. The doped ceria usually has
enhanced catalytic and electrical properties, which depend on a series of factors
such as the particle size, the structural characteristics, morphology etc. Ceria based
solid solutions have been widely identified as promising electrolytes for
intermediate temperature solid oxide fuel cells (SOFC). The success of many
promising device technologies depends on the suitable powder synthesis
techniques. The challenge for introducing new nanopowder synthesis techniques is to preserve high material quality while attaining the desired composition. The
method adopted should give reproducible powder properties, high yield and must
be time and energy effective. The use of a variety of new materials in many
technological applications has been realized through the use of thin films of these
materials. Thus the development of any new material will have good application
potential if it can be deposited in thin film form with the same properties. The
advantageous properties of thin films include the possibility of tailoring the
properties according to film thickness, small mass of the materials involved and
high surface to volume ratio. The synthesis of polymer nanocomposites is an
integral aspect of polymer nanotechnology. By inserting the nanometric inorganic
compounds, the properties of polymers can be improved and this has a lot of
applications depending upon the inorganic filler material present in the polymer.
Vijayan, K K; Dr.Abdul Rasheed, T M(Cochin University Of Science And Technology, October 8, 2003)
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Abstract:
The central theme of this research concerns the study of vibrationally excited
molecules. We have used the local mode description of such vibrational states, and this
-model has now gained general acceptance. A central feature of the model is the
Wloealizafion of vibrational energy. A study of these high—energy localized states provides
example, becauseof this localization, overtone spectra, which measure the absorption of
T vibrational energy, are extremely sensitive to the properties of X-H bonds. We also use
-overtone spectra to study the conformation of molecules, i.e., the relative internal
orientation of their bonds. The thesis comprises six chapters
Description:
Department of Physics Cochin
University of Science and Technology
The present study is an attempt to find out the ralation between RNA/DNA ratio, protein,percentage growth rate and specific growth rate of prawn,Penaeus indicus with respect to Nervous system, Eyestalk and Muscle tissues during ontogenesis. We have isolated and purified a natural agglutinin in the hemolymph of P.indicus with antigenecity, agglutinating, hemolytic and antibacterial properties. The influence of growth and environmental parameters on the level of agglutinin in the hemolymph was studied. Agglutinin concentration during normal growth process was compared. The agglutinin concentration in the hemolymph was quantified through developing ELISA, which is useful in health monitoring studies of individual species. Complete amino acid composition of both the subunits of P.indicus agglutinin were analysed. P.indicus agglutinin showed similarity to those proteins having antigenecity,hemolytic and agglutinating properties.Hence, agglutinin was considered as a natural defence protein in the hemolymph of P.indicus responsible for immune surveillance. The humoral defence mechanism of agglutinin was a co-operative effort with hemocytes and complement system. The composition of isolated agglutinin of P.indicus amino acids will be helpful in the synthesis of new antibacterial analogues which can be used against disease causing organisms.
Description:
Dept. of Biotechnology, Cochin University of Science and Technology
Bijina, B; Dr.Chandrasekaran,M(Cochin University of Science & Technology, May , 2006)
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Abstract:
Protease inhibitors are one of the most important tools of nature for
regulating the proteolytic activity of their target proteases. They are
synthesized in biological systems and they play a critical role in controlling
a number of diverse physiological functions. The current investigation
focused on the isolation, purification and characterization of a novel
protease inhibitor from Moringa oleifera. The results obtained during the
course of study opens new perspectives for the utilization of protease
inhibitor from Moringa oleifera for various pharmaceutical, agricultural and
food industries. The biological and physicochemical properties exhibited by
the novel protease inhibitor from Moringa oleifera clearly testify its
suitability for the development as a drug for application in pharmaceutical
industries such as anticoagulant agent or biocontrol agent in agriculture and
even as a food preservant. There is a scope for further research on the
structure elucidation and protein engineering towards a wide range of
further applications. Detailed structure/function analysis of these proteins is
important to facilitate their use in genetic engineering for various
applications.
Description:
Department of Biotechnology,
Cocbin 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
Thomas,P T; George,K K(Department of Applied Economics, September , 1994)
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Abstract:
It is hoped that the present study by analysing the
dynamics of agrarian change and peasant mobility may contribute
to the on-going debate on this issue in India and other developing
countries. It may also help to throw light on the validity of some
of the theories formulated on the basis of experience in different
regions and at different times. The study is likely to be of
special importance as it covers an area which has one of the
highest densities of population. The area has also witnessed
sweeping changes in agrarian structure as a result of the most
radical land reforms among the Indian states.
Abdul Rasheed, T M; Dr.Narayanan Nampoori, V P(Cochin University of Science and Technology, September 16, 1987)
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Abstract:
Vibrational overtone spectroscopy of X-H (X=C,N,O) containing molecules is an area of recent interest. The spectroscopic studies of higher vibrational levels yield valuable informations, regarding,the molecular structure, intra- and inter-molecular interactions, radiationless transitions, intra-molecular vibrational relaxations, multiphoton excitations and chemical reactivities, which cannot be z obtained by other spectroscopic methods. This thesis presents the results of experimental investigations on the overtone spectra of some organic compounds in the liquid phase for the characterization of CH bonds. The spectra in the fifth overtone region (1fiV=6) are recorded using a dual beam thermal lens setup and the lower overtones (.AV=2-5) are recorded spectrophotometrically.The thesis is presented in six chapters.
Description:
Department of Physics,Cochin University of Science and Technology
Shibu, Eappen M; Dr.Rajappan Nair,K P(Cochin University of Science and Technology, April 4, 2003)
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Abstract:
Near-infrared spectroscopy can be a workhorse technique for materials
analysis in industries such as agriculture, pharmaceuticals, chemicals and polymers. A
near-infrared spectrum represents combination bands and overtone bands that are
harmonics of absorption frequencies in the mid-infrared. Near-infrared absorption
includes a combination-band region immediately adjacent to the mid-infrared and three
overtone regions. All four near-infrared regions contain "echoes" of the fundamental mid-infrared
absorptions. For example, vibrations in the mid-infrared due to the C-H stretches will
produce four distinct bands in each of the overtone and combination regions. As the
bands become more removed from the fundamental frequencies they become more
widely separated from their neighbors, more broadened and are dramatically reduced in
intensity. Because near-infrared bands are much less intense, more of the sample can be
used to produce a spectra and with near-infrared, sample preparation activities are
greatly reduced or eliminated so more of the sample can be utilized. In addition, long
path lengths and the ability to sample through glass in the near-infrared allows samples
to be measured in common media such as culture tubes, cuvettes and reaction bottles.
This is unlike mid-infrared where very small amounts of a sample produce a strong
spectrum; thus sample preparation techniques must be employed to limit the amount of
the sample that interacts with the beam. In the present work we describe the successful the fabrication and calibration of a linear high resolution linear spectrometer using tunable diode laser and a 36 m path length cell and meuurement of a highly resolved structure of OH group in methanol in the transition region A v =3. We then analyse the NIR spectrum of certain
aromatic molecules and study the substituent effects using local mode theory
Description:
Department of Physics, Cochin University of Science and Technology