Nisha Nandakumar; Dr. Philip Kurian(Cochin University of Science and Technology, December 3, 2013)
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Abstract:
The Human race of our century is in gluttonous search for novel engineering
products which led to a skyrocketed progress in research and fabrication of filled
polymers. Recently, a big window has been opened up for speciality polymers
especially elastomers with promising properties. Among the many reasons why
rubbers are widely used in the process industries, three are considered as
important. Firstly, rubbers operate in a variety of environments and possess usable
ranges of deformity and durability and can be exploited through suitable and more
or less conventional equipment design principles. Secondly, rubber is an eminently
suitable construction material for protection against corrosion in the chemical plant
and equipment against various corrosive chemicals as, acids and alkalies and if
property tailored, can shield ionising radiations as X-rays and gamma rays in
medical industry, with minimum maintenance lower down time, negligible
corrosion and a preferred choice for aggressive corroding and ionising
environment. Thirdly, rubber can readily and hastily, and at a relatively lower cost,
be converted into serviceable products, having intricate shapes and dimensions. In a
century’s gap, large employment of flexible polymer materials in the different
segments of industry has stimulated the development of new materials with special
properties, which paved its way to the synthesis of various nanoscale materials. At
nano scale, one makes an entry into a world where multidisciplinary sciences meet
and utilises the previously unapproached infinitesimal length scale, having
dimension which measure upto one billionth of a meter, to create novel properties.
The nano fillers augment the elastomers properties in an astonishing fashion due to
their multifunctional nature and unprecedented properties have been exhibited by
these polymer-nanocomposites just to beat the shortcomings of traditional micro
composites. The current research aims to investigate the possibility of using
synthesised nano barium sulphate for fabricating elastomer-based nanocomposites
and thereby imparting several properties to the rubber. In this thesis, nano
materials, their synthesis, structure, properties and applications are studied. The
properties of barium sulphate like chemical resistance and radiopacity have been
utilized in the present study and is imparted to the elastomers by preparing
composites.
Nisha, Nandakumar; Dr. Philip, Kurian(Cochin University of Science And Technology, December 11, 2013)
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Abstract:
The Human race of our century is in gluttonous search for novel engineering
products which led to a skyrocketed progress in research and fabrication of filled
polymers. Recently, a big window has been opened up for speciality polymers
especially elastomers with promising properties. Among the many reasons why
rubbers are widely used in the process industries, three are considered as
important. Firstly, rubbers operate in a variety of environments and possess usable
ranges of deformity and durability and can be exploited through suitable and more
or less conventional equipment design principles. Secondly, rubber is an eminently
suitable construction material for protection against corrosion in the chemical plant
and equipment against various corrosive chemicals as, acids and alkalies and if
property tailored, can shield ionising radiations as X-rays and gamma rays in
medical industry, with minimum maintenance lower down time, negligible
corrosion and a preferred choice for aggressive corroding and ionising
environment. Thirdly, rubber can readily and hastily, and at a relatively lower cost,
be converted into serviceable products, having intricate shapes and dimensions. In a
century’s gap, large employment of flexible polymer materials in the different
segments of industry has stimulated the development of new materials with special
properties, which paved its way to the synthesis of various nanoscale materials. At
nano scale, one makes an entry into a world where multidisciplinary sciences meet
and utilises the previously unapproached infinitesimal length scale, having
dimension which measure upto one billionth of a meter, to create novel properties.
The nano fillers augment the elastomers properties in an astonishing fashion due to
their multifunctional nature and unprecedented properties have been exhibited by
these polymer-nanocomposites just to beat the shortcomings of traditional micro
composites. The current research aims to investigate the possibility of using
synthesised nano barium sulphate for fabricating elastomer-based nanocomposites
and thereby imparting several properties to the rubber. In this thesis, nano
materials, their synthesis, structure, properties and applications are studied. The
properties of barium sulphate like chemical resistance and radiopacity have been
utilized in the present study and is imparted to the elastomers by preparing
composites
Description:
Department of Polymer Science and Rubber Technology
Cochin University of Science and Technology
Nisha, V S; Rani, Joseph(Dept. of Polymer Science and Rubber Technology, May , 2006)
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Abstract:
The present work is to impart radiopacity in various natural polymers like chitosan, natural rubber and derivatives of chitosan and to characterize it. This thesis collated the radiopaque properties of these radiopaque polymers and various technological applications in the medical field. The applications of radiopaque polymers leads to an exploitation of radiopaque properties like X-ray visibility, optical density, effective atomic number, attenuation coefficient of biopolymers like chitosan, chitosan formate, chitosan acetate, carboxy methyl chitosan and natural rubber. The radiopaqe properties of these materials highly depend upon the size, shape, amount of radiopacifier and crystallinity of the radiopaque material. Radiopaque chitosan microspheres were prepared by cross linking with glutaraldehyde followed by the encapsulation of barium sulpahte. The effect of different emulsion systems on the morphology of chitosan microspheres were studied. The study concentrates radiopaque natural rubber for shielding applications. It reveals that to improve the particle size, morphology and crystalline phase of the zinc oxide particles, a novel method for the preparation of zinc oxide is adopted. A detailed radiopacity study was done in natural rubber containing 100phr precipitated zinc oxide prepared from different zinc salts. One of the significant findings of this investigation is that NR vulcanizates containing precipitated zinc oxide (from zinc acetate) shows higher attenuation coefficient. These interesting findings reveal the applications of these natural radiopaque systems in various fields like surgical tools, medical tubings, catheters, radiation shielding,etc.
Mini, P P; Dr.Arunachalam, P(Cochin University Of Science And Technology, June , 2013)
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Abstract:
Health insurance has become a necessity for the common man,
next to food, clothing and shelter. The financing of health expense is either catastrophic or sometimes even frequently contracted illnesses, is a
major cause of mental agony for the common man. The cost of care may
sometimes result in the complete erosion of the family savings or may
even lead to indebtedness as many studies on causes of rural
indebtedness bear testimony (Jayalakshmi, 2006). A suitable cover by way
of health insurance is all that is required to cope with such situations.
Health care insurance rightly provides the mechanism for both
individuals and families to mitigate the financial burden of medical
expenses in the present context. Hence a well designed affordable health
insurance policy is the need of the hour.Therefore, it is very significant to study the extent to which the
beneficiaries in Kerala make use of the benefits provided by a social health
insurance scheme like RSBY-CHIS. Based on the above pertinent points, this
study assumes national relevance even though the geographical area of the
study is limited to two districts of Kerala. The findings of the study will bring
forth valuable inputs on the services availed by the beneficiaries of RSBYCHIS
and take appropriate measures to improve the effectiveness of the scheme
whereby maximum quality benefit could be availed by the poorest of the poor
and develop the scheme as a real dawn of the new era of health for them
Description:
Department of Applied Economics,
Cochin University of Science and Technology
Supriya, M H; Dr.Pillai, P R S(Cochin University of Science & Technology, October , 2007)
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Abstract:
This thesis addresses one of the emerging topics in Sonar Signal Processing.,viz.the implementation of a target classifier for the noise sources in the ocean, as the operator assisted classification turns out to be tedious,laborious and time consuming.In the work reported in this thesis,various judiciously chosen components of the feature vector are used for realizing the newly proposed Hierarchical Target Trimming Model.The performance of the proposed classifier has been compared with the Euclidean distance and Fuzzy K-Nearest Neighbour Model classifiers and is found to have better success rates.The procedures for generating the Target Feature Record or the Feature vector from the spectral,cepstral and bispectral features have also been suggested.The Feature vector ,so generated from the noise data waveform is compared with the feature vectors available in the knowledge base and the most matching pattern is identified,for the purpose of target classification.In an attempt to improve the success rate of the Feature Vector based classifier,the proposed system has been augmented with the HMM based Classifier.Institutions where both the classifier decisions disagree,a contention resolving mechanism built around the DUET algorithm has been suggested.
Description:
Departement of Electronics,Cochin University of Science and Technology
Raghu, O; Dr. Jacob, Philip(Cochin University of Science and Technology, February , 2007)
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Abstract:
Among the large number of photothcrmal techniques available, photoacoustics
assumes a very significant place because of its essential simplicity and the variety of
applications it finds in science and technology. The photoacoustic (PA) effect is the
generation of an acoustic signal when a sample, kept inside an enclosed volume, is
irradiated by an intensity modulated beam of radiation. The radiation absorbed by the
sample is converted into thermal waves by nonradiative de-excitation processes. The
propagating thermal waves cause a corresponding expansion and contraction of the
gas medium surrounding the sample, which in tum can be detected as sound waves by
a sensitive microphone. These sound waves have the same frequency as the initial
modulation frequency of light. Lock-in detection method enables one to have a
sufficiently high signal to noise ratio for the detected signal. The PA signal amplitude
depends on the optical absorption coefficient of the sample and its thermal properties.
The PA signal phase is a function of the thermal diffusivity of the sample.Measurement of the PA amplitude and phase enables one to get valuable information
about the thermal and optical properties of the sample.
Since the PA signal depends on the optical and thennal properties of the
sample, their variation will get reflected in the PA signal. Therefore, if the PA signal
is collected from various points on a sample surface it will give a profile of the
variations in the optical/thennal properties across the sample surface. Since the optical
and thermal properties are affected by the presence of defects, interfaces, change of
material etc. these will get reflected in the PA signal. By varying the modulation
frequency, we can get information about the subsurface features also. This is the basic
principle of PA imaging or PA depth profiling. It is a quickly expanding field with
potential applications in thin film technology, chemical engineering, biology, medical
diagnosis etc. Since it is a non-destructive method, PA imaging has added advantages
over some of the other imaging techniques. A major part of the work presented in this
thesis is concemed with the development of a PA imaging setup that can be used to
detect the presence of surface and subsmface defects in solid samples.Determination of thermal transport properties such as thermal diffusivity,
effusivity, conductivity and heat capacity of materials is another application of
photothennal effect. There are various methods, depending on the nature of the
sample, to determine these properties. However, there are only a few methods
developed to determine all these properties simultaneously. Even though a few
techniques to determine the above thermal properties individually for a coating can be
found in literature, no technique is available for the simultaneous measurement of
these parameters for a coating. We have developed a scanning photoacoustic technique that can be used to determine all the above thermal transport properties
simultaneously in the case of opaque coatings such as paints. Another work that we
have presented in this thesis is the determination of thermal effusivity of many bulk
solids by a scanning photoacoustic technique. This is one of the very few methods
developed to determine thermal effiisivity directly.
Description:
Dept.of Instrumentation,Cochin University of Science and Technology