Preetha Nair, K; Dr.Rani, Joseph; Dr.Mathiazhagan, A(Cochin University of Science and Technology, July 17, 2013)
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Abstract:
The current research investigates the possibility of using unmodified and modified nanokaolin, multiwalled carbon nanotube (MWCNT) and graphene as fillers to impart enhancement in mechanical, thermal, and electrical properties to the elastomers. Taking advantage of latex blending method, nanoclay, MWCNT and graphene dispersions, prepared by ultra sound sonication are dispersed in polymer latices. The improvement in material properties indicated better interaction between filler and the polymer.MWCNT and graphene imparted electrical conductivity with simultaneous improvement in mechanical properties. Layered silicates prepared by microwave method also significantly improve the mechanical properties of the nanocomposites. The thesis entitled ‘Studies on the use of Nanokaolin, MWCNT and Graphene in NBR and SBR’ consists of ten chapters. The first chapter is a concise introduction of nanocomposites, nanofillers, elastomeric matrices and applications of polymer nanocomposites. The state-of-art research in elastomer based nanocomposites is also presented. At the end of this chapter the main objectives of the work are mentioned. Chapter 2 outlines the specifications of various materials used, details of experimental techniques employed for preparing and characterizing nanocomposites. Chapter3 includes characterization of the nanofillers, optimsation of cure time of latex based composites and the methods used for the preparation of latex based and dry rubber based nanocomposites. Chapter4 presents the reinforcing effect of the nanofillers in XNBR latex and the characterization of the nanocomposites. Chapter5 comprises the effect of nanofillers on the properties of SBR latex and their characterization Chapter 6 deals with the study of cure characteristics, mechanical and thermal properties and the characterization of NBR based nanocomposites.
Chapter7 is the microwave studies of MWCNT and graphene filled elastomeric nanocomposites. Chapter 8 gives details of the preparation of layered silicates, their characterization and use in different elastomeric matrices. Chapter 9 is the study of mechanical properties of nanoclay incorporated nitrile gloves .Chapter 10 presents the summary and conclusions of the investigation.
The present study on the vertical structure of horizontal wind variability in the surface boundary layer over Sriharikota. Based on clock wind speed and direction measuring meteorological tower facility from seven levels in the 100 m layer. The study on wind variability and elliptical approximation of wind hodographs investigated for this tropical coastal station established that Sriharikota is of meso-scale weather entity. Wind variability ratio increases from lower levels to upper levels. In South West monsoon months the station is of high ratio values and it gets affected with meso-scale weather features like thunderstorms. Average total shears are observed greater values than scalar shears. Scalar shears are high in the lowest shear levels compared to upper levels. Semi diurnal types of oscillation in average total shears are found in south west monsoon months. During cyclonic storm passage it is observed that there can be significant difference in mean wind speed from 10 m to 100 m level, but it is not so for peak wind speeds. The variations in wind variability ratio in different months is clearly depicted its strong link to define meso-scale or synoptic –scale forcing domination for this station. Meso-scale forcing is characterized by diurnal wind variability and synoptic- scale forcing by interdiurnal wind variability.
Joseph, Babitha; Dr Prathapachantra Kurup, M R(Cochin University of Science And Technology, November 20, 2014)
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Abstract:
The ability of aroylhydrazones to bind with transition metals is a
developing area of research interest and the coordinating properties of
hydrazones can be tuned by the appropriate choice of parent aldehyde or
ketone and the hydrazide. So in the present work we selected four different
aroylhydrazones as principal ligands. Introduction of heterocyclic bases like
1,10-phenanthroline, 2,2′-bipyridine, 3-picoline and pyridine leads to the
syntheses of mixed ligand metal chelates which can cause different bonding
modes, spectral properties and geometries in coordination compounds. The
importance of aroylhydrazones and their complexes in various fields and their
interesting coordinating properties stimulate our interest in the investigation of
transition metal chelates with four different aroylhydrazones. The aroylhydrazones
selected are 4-benzyloxy-2-hydroxybenzaldehyde-4-nitrobenzoylhydrazone
dimethylformamide monosolvate, 5-bromo-2-hydroxy-3-methoxybenzaldehyde
nicotinoylhydrazone dihydrate methanol monosolvate, 4-diethylamino-2-
hydroxybenzaldehyde nicotinoylhydrazone monohydrate and 2-benzoylpyridine-
4-nitrobenzoylhydrazone. The selection of 4-benzyloxy-2-hydroxybenzaldehyde-
4-nitrobenzoylhydrazone was based on the idea of developing ligands having
D-π-A general structure, so that the proligand and metal complexes exhibit
NLO activity. Hence it is interesting to explore the coordinating capabilities
of the synthesized hydrazones and to study the NLO activity of hydrazones
and some of the metal complexes.
Rajesh,K Thumabakara; Thrivikraman,T(Department of Mathematics, March , 2006)
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The fuzzy set theory has a wider scope of applicability than classical set theory in solving various problems. Fuzzy set theory in the last three decades as a formal theory which got formalized by generalizing the original ideas and concepts in classical mathematical areas and as a very powerful modeling language, that can cope with a large fraction of uncertainties of real life situations. In Intuitionistic Fuzzy sets a new component degree of non membership in addition to the degree of membership in the case of fuzzy sets with the requirement that their sum be less than or equal to one. The main objective of this thesis is to study frames in Fuzzy and Intuitionistic Fuzzy contexts.
The thesis proved some results such as ifµ is a fuzzy subset of a frame F, then µ is a fuzzy frame of F iff each non-empty level subset µt of µ is a subframe of F, the category Fuzzfrm of fuzzy frames has products and the category Fuzzfrm of fuzzy frames is complete. It define a fuzzy-quotient frame of F to be a fuzzy partition of F, that is, a subset of IF and having a frame structure with respect to new operations and study the notion of intuitionistic fuzzy frames and obtain some results and introduce the concept of Intuitionistic fuzzy Quotient frames. Finally it establish the categorical link between frames and intuitionistic fuzzy topologies.
Joy, E C; Dr.Joy, George(Cochin University Of Science And Technology, March 27, 1980)
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This thesis consists of a study of the effect of electrode films and overlayer films on the electrical properties of certain metal films. The films have been prepared on glass substrates by thermal evapouration in a vaccum 10 terr. The properties of Al films on Ag, Al,Au and Cu films on In electrodes ,and Bi/Ag bilayer films have been studied. The influence of annealing electrodes at higher temperature on the electrical properties of metal films has also been investigated. Further the effect of varying layer thickness in the bilayer films ,both annealed at higher temperature and annealed at room temperature have been examined.
Description:
Department Of Physics,Cochin University Of Science And Technology
Pradeep,B; Dr.Joy, George(Cochin University of Science And Technology, November , 1986)
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This thesis deals with the preparation and properties of two compounds of V-II family, viz.
bismuth telluride and bismuth oxide, in thin filmform. In the first chapter is given the resume of
basic solid state physics relevant to the work reported here. In the second chapter the different
methods of thin film preparationtia described. Third chapter deals with the experimental techniques used for preparation and characterization of the films. Fourth chapter deals with the preparation and propertiesof bismuth telluride films. In next four chapters, the preparation and properties of bismuth oxide films are discussed in detail. In the last chapter the use of Bi205 films in the fabrication of Heat mirrors is examined and discussed.
Description:
Department of physics, Cochin University of Science And Technology
Marina, Aloysius; Dr. Parameswaran, K(Space Physics Laboratory, Vikram Sarabhai Space Centre, January , 2010)
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Abstract:
The present study brings out the influence of transport dynamics on the
aerosol distribution over the Indian region at a few selected geographically distinct
locations. Over the Bay of Bengal the dominant pathway of aerosol transport during the
pre-monsoon period is through higher altitudes (~ 3 km); directed from the Indian main
land. In contrast, the aerosol pathways over the Arabian Sea during the same period are
quite complex. They are directed from geographically different environments around the
ocean through different altitudes. However in general, the day-to-day variability of AOD at
both these regions is significantly influenced by the features of atmospheric circulation
especially, the wind convergence at higher altitudes (around 3 km). Over the Ganga Basin
during the winter period, the wind convergence at lower altitudes (< I km) govems the
shon term variations in AOD, while the mean AOD distribution at this location is mainly
governed by the local anthropogenic sources.
Sunny, Kuriakose A; Dr.Thrivikraman, T(Department of Mathematics and Statistics, August , 1993)
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Abstract:
In this study we combine the notions of fuzzy order
and fuzzy topology of Chang and define fuzzy ordered
fuzzy topological space. Its various properties are
analysed. Product, quotient, union and intersection
of fuzzy orders are introduced. Besides, fuzzy order
preserving maps and various fuzzy completeness are
investigated. Finally an attempt is made to study the
notion of generalized fuzzy ordered fuzzy topological
space by considering fuzzy order defined on a fuzzy subset.