Roshini, Thumpakara K; Dr.Prathapan, S(Cochin University of Science & Technology, November , 2007)
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Abstract:
The synthesis and reactions of simple derivatives of 2(3H)- and 3(2H)furanones
have attracted considerable attention in recent years, primarily in
connection with development of routes to antitumor agents that contain this
ring as central structural unit. They also serve as useful synthetic building
blocks for lactones and furans and are the precursors of a wide variety of
biologically important heterocyclic systems. Although a number of syntheses
of furanones were known they were in many cases limited to specific
substitution pattems. The development of altemative strategies for the
preparation of these heterocycles is therefore of considerable importance or
continues to be a challenge.We propose to develop new and general approaches to the synthesis of
furanone ring systems from simple and readily available starting materials
since we were interested in examining their rich photochemistry. The
photochemical reactivity of Beta,gama-unsaturated lactams and lactones is a subject of current interest. Some of the prominent photoreaction pathways of
unsaturated lactones include decarbonylation, solvent addition to double
bonds, decarboxylation, migration of aryl substituents and dimerisation. lt
was reported earlier that the critical requirement for clean photochemical
cleavage of the acyl-oxygen bond is the presence ofa double bond adjacent to
the ether oxygen and 2(3H)-furanones possessing this structural requirement
undergo facile decarbonylation. But related phenanthrofuranones are isolated
as photostable end products upon irradiation. Hence we propose to synthesis a
few phenanthro-2(3H)-furanones to study the effect of a radical stabilising
group at 3-position of furanone ring on photolysis. To explore the tripletmediated
transformations of 2(3H)-furanones in polar and nonpolar solvents a
few 3,3-bis(4-chlorophenyl)-5-aryl-3H-furan-2-ones and 3,3-di(p-tolyl)-5-aryl-
3H-furan-2-ones were synthesised from the corresponding
dibenzoylstyrene precursors by neat thermolysis. Our aim was to study the
nature of intermediates involved in these transformations.We also explored the possibility of developing a new and general
approach to the synthesis of 3(2H)-furanones from simple and readily
available starting materials since such general procedures are not available.
The protocol developed by us employs readily available phenanthrenequinone
and various 4-substituted acetophenones as starting materials and provides
easy access to the required 3(2H)-furanone targets. These furanone
derivatives have immense potential for further investigations .We also aimed the synthesis of a few dibenzoylalkene-type systems
such as acenaphthenone-2—ylidene ketones and phenanthrenone-9-ylidene
ketones. These systems were expected to undergo thermal rearrangement to
give furanones and spirofuranones. Also these systems can be categorised as
quinonemethides which are valuable synthetic intermediates.
Description:
Department of Applied Chemistry, Cochin University of Science
and Technology
Pyroja, S; Paulose,C S(Department of Biotechnology, Faculty of Science, April , 2002)
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Abstract:
The work is an attempt to understand the role of 5-HT, 5-HT1A and 5-HT2C receptors in the regulation of liver cell proliferation using in vivo and in vitro models. The work also focuses on the brain serotonergic changes associated with hapatocyte proliferation and apoptosis to delineate its regulatory function. The investigation of mechanisms involving different models of hepatocyte proliferation contributes to our knowledge about serotonergic regulation of cell growth, apoptosis and carcinogenesis of liver. The study reveals that the alteration of the 5-HT1A and 5-HT2C receptor function and gene expression in the brain stem, cerebral cortex and hypothalamus play an important role in the sympathetic regulation of cell proliferation, neoplastic transformation and apoptosis. The functional balance between 5-HT1A and 5-HT2C receptor plays an important role in regulating hepatocyte proliferation, neoplastic transformation and hepatic apoptosis. The regulatory role of 5-HT1A and 5-HT2C receptor during neoplastic transformation and apoptosis could lead to possible therapeutic intervention in the treatment of cancers and have immense clinical importance.
Baby,Jacob; Dr.Sankaranarayanan, K C(Cochin University of Science and Technology, March 1, 1985)
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Abstract:
An attempt is made to identify the causes for the decline of Kerala’s agricultural export performance. The study evaluates the policies of the government and programmes of the organization assigned with the task of development of export trade of specific commodities. The researcher recommends a plan of action with long term perspective and suggests appropriate strategies for the export development of the traditional and nontraditional agricultural items. T he thesis also review trends in the world trade of the major exports from Kerala
Description:
Department of Applied Economics, Cochin University of Science and Technology
Anil,R Nair; Dr.Sadasivan Nair,G(Cochin University Of Science And Technology, October 20, 2009)
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Abstract:
Access to education becomes an issue of equity with diverse
claims from stakeholders justifying their rights based on perceptions
of equity — both social and individual. In-spite of the phenomenal
increase since independence in the number of institutions imparting
education and the number of beneficiaries, India being the second
largest nation in terms of population of the young finds its resources
spread thin in meeting the demand for education. Quality education
comes at a premium in India whether it is provided in the private or
in the public sector. Education seemingly enables the individuals,
singly and collectively. to overcome the social barriers perpetuated
by the caste system. Taken together, these unleash grave demands on formulating equitable standards. It is in this context that
identifying the deserving for favourable consideration becomes all
the more important.
In this sea of claims and counter-claims, this thesis tries to
identify the issues involved on the question of equitable access to
education on the basis of the factual position in the field of
education. Identifying the issues correctly provides the necessary
impetus for framing the questions that provide meaningful answers.
The objective of this research is to help formulate the policy
guidelines governing the principles of equity that is needed to
ensure universal access to education in India.
Description:
School of Legal Studies, Cochin University of Science and
Technology
Binsy,Varghese V; Dr.Sugunan, S(Cochin University Of Science And Technology, February , 1998)
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Abstract:
Catalysis research underpins the science of modern chemical processing
and fuel technologies. Catalysis is commercially one of the most important
technologies in national economies. Solid state heterogeneous catalyst materials such
as metal oxides and metal particles on ceramic oxide substrates are most common.
They are typically used with commodity gases and liquid reactants. Selective oxidation
catalysts of hydrocarbon feedstocks is the dominant process of converting them to key
industrial chemicals, polymers and energy sources.[1]
In the absence of a unique successfiil theory of heterogeneous catalysis,
attempts are being made to correlate catalytic activity with some specific properties of
the solid surface. Such correlations help to narrow down the search for a good catalyst
for a given reaction.
The heterogeneous catalytic performance of material depends on many
factors such as [2]
Crystal and surface structure of the catalyst.
Thermodynamic stability of the catalyst and the reactant.
Acid- base properties of the solid surface.
Surface defect properties of the catalyst.Electronic
and semiconducting properties and the band structure.
Co-existence of dilferent types of ions or structures.
Adsorption sites and adsorbed species such as oxygen.Preparation method of catalyst , surface area and nature of heat treatment.
Molecular structure of the reactants.
Many systematic investigations have been performed to correlate
catalytic performances with the above mentioned properties. Many of these
investigations remain isolated and further research is needed to bridge the gap in the
present knowledge of the field.
Description:
Department of Applied Chemistry, Cochin University of Science & Technology
Jasmine, Mathew; Dr. Ebenezer, D D(Defence Research and Development Organisation, September , 2011)
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Abstract:
New mathematical methods to analytically investigate linear acoustic radiation
and scattering from cylindrical bodies and transducer arrays are presented. Three
problems of interest involving cylinders in an infinite fluid are studied. In all the three
problems, the Helmholtz equation is used to model propagation through the fluid and the
beam patterns of arrays of transducers are studied.
In the first problem, a method is presented to determine the omni-directional and
directional far-field pressures radiated by a cylindrical transducer array in an infinite
rigid cylindrical baffle. The solution to the Helmholtz equation and the displacement
continuity condition at the interface between the array and the surrounding water are
used to determine the pressure. The displacement of the surface of each transducer is in
the direction of the normal to the array and is assumed to be uniform. Expressions are
derived for the pressure radiated by a sector of the array vibrating in-phase, the entire
array vibrating in-phase, and a sector of the array phase-shaded to simulate radiation
from a rectangular piston. It is shown that the uniform displacement required for
generating a source level of 220 dB ref. μPa @ 1m that is omni directional in the
azimuthal plane is in the order of 1 micron for typical arrays. Numerical results are
presented to show that there is only a small difference between the on-axis pressures
radiated by phased cylindrical arrays and planar arrays. The problem is of interest
because cylindrical arrays of projectors are often used to search for underwater objects.
In the second problem, the errors, when using data-independent, classical, energy
and split beam correlation methods, in finding the direction of arrival (DOA) of a plane
acoustic wave, caused by the presence of a solid circular elastic cylindrical stiffener near
a linear array of hydrophones, are investigated. Scattering from the effectively infinite
cylinder is modeled using the exact axisymmetric equations of motion and the total
pressures at the hydrophone locations are computed. The effect of the radius of the
cylinder, a, the distance between the cylinder and the array, b, the number of
hydrophones in the array, 2H, and the angle of incidence of the wave, α, on the error in
finding the DOA are illustrated using numerical results. For an array that is about 30
times the wavelength and for small angles of incidence (α<10), the error in finding the
DOA using the energy method is less than that using the split beam correlation method
with beam steered to α; and in some cases, the error increases when b increases; and the errors in finding the DOA using the energy method and the split beam correlation
method with beam steered to α vary approximately as a7 / 4 . The problem is of interest
because elastic stiffeners – in nearly acoustically transparent sonar domes that are used to
protect arrays of transducers – scatter waves that are incident on it and cause an error in
the estimated direction of arrival of the wave.
In the third problem, a high-frequency ray-acoustics method is presented and
used to determine the interior pressure field when a plane wave is normally incident on a
fluid cylinder embedded in another infinite fluid. The pressure field is determined by
using geometrical and physical acoustics. The interior pressure is expressed as the sum
of the pressures due to all rays that pass through a point. Numerical results are presented
for ka = 20 to 100 where k is the acoustic wavenumber of the exterior fluid and a is the
radius of the cylinder. The results are in good agreement with those obtained using field
theory. The directional responses, to the plane wave, of sectors of a circular array of
uniformly distributed hydrophones in the embedded cylinder are then computed. The
sectors are used to simulate linear arrays with uniformly distributed normals by using
delays. The directional responses are compared with the output from an array in an
infinite homogenous fluid. These outputs are of interest as they are used to determine the
direction of arrival of the plane wave. Numerical results are presented for a circular array
with 32 hydrophones and 12 hydrophones in each sector. The problem is of interest
because arrays of hydrophones are housed inside sonar domes and acoustic plane waves
from distant sources are scattered by the dome filled with fresh water and cause
deterioration in the performance of the array.
Deepthi, Augustine; Dr.Rosamma, Philip(Cochin University of Science And Technology, May , 2014)
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Abstract:
The thesis is comprised of seven chapters. Chapter 1 gives a general introduction to marine actinomycetes; Chapter 2 gives an account on the morphological, biochemical and physiological characterization of marine actinomycetes. Comprehensive description of molecular identification and phylogenetic analysis of actinomycetes is dealt with in Chapter 3. The antimicrobial property with special reference to antivibrio activity is described in Chapter 4. Chapter 5 explores the melanin production ability of marine actinomycetes, characterization of melanin and evaluation of its bioactivity. Chapter 6 illustrates the study on chitinolytic Streptomyces as antifungal and insecticidal agents. Summary and Conclusion of the study is presented in Chapter 7, followed by References and Appendices.The present study provides an insight into the various actinomycetes occurring in the sediments of Arabian Sea and Bay of Bengal. Streptomyces was found to be the dominant group followed by Nocardiopsis. Eventhough generic level identification is possible by traditional phenotypic methods, species level identification necessitate a polyphasic approach including both phenotypic and genotypic characterization. Antibiotic production coupled with biogranulation property helped in the effective utilization of the actinomycetes for the control of vibrios. Melanin from Streptomyces bikiniensis was proved to be a promising antioxidant and photoprotectant. Marine actinomycetes were found to be a good source of hydrolytic enzymes and the chitinolytic isolates could be explored as biocontrol agents in terms of antifungal and insecticidal property. The present study explored the potential of marine actinomycetes especially Streptomycetes as a promising source of bioactive molecules for application in aquaculture and pharmaceutical industry.