Priya Rani, M; Dr. Padmakumari Amma, K. P.; Dr. Raghu, K. G.(Cochin University of Science & Technology, June , 2014)
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Abstract:
Plants and microorganisms provide the pharmaceutical industry with some of the most important sources of components for the research of new medications This thesis involves the study of three medicinal plants belonging to three different important families viz, Cyperus rotundus (Cyperaceae), Stereospermum colais (Bignoniaceae) as well as the well known medicinal plant Zingiber officinale (Zingiberaceae) as the third. The first chapter gives an overview of biologically active natural products with special reference to antioxidant, antidiabetic, anti-inflammatory and antimicrobial molecules from terrestrial sources. Chapter 2 of the thesis deals with the isolation of phytochemical constituents of the medicinal plant Cyperus rotundus and its antioxidant and radical scavenging potential. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais,
A Bignoniaceae plant belonging to the genus Stereospermum which is used extensively. Chapter 3 of the thesis describes the studies on the roots of Stereospermum colais, a Bignoniaceae plant belonging to the genus Stereospermum which is used extensively in Ayurveda. Chapter 4 describes the biological potential of rhizomes of Zingiber officinale. Ethyl acetate extract of ginger (EAG) possessed antioxidant activity as is evident from the results of various in vitro assays compared to other extracts .In conclusion, medicinal plants Cyperus rotundus and Stereospermum colais have been analysed for their phytochemical constituents. Also, the positive results obtained from biological activity studies such as antioxidant, anti-inflammatory and antimicrobial activity on the isolated compounds/extracts add on to the medicinal properties of these plants. Apart from that, ethyl acetate extract of Zingiber officinale (ginger) rhizomes has been shown to have very good biological potential including glucose lowering and adipocyte differentiation inhibitory effect.
Sobha, A; Dr.Syamaprasad,U(Cochin University of Science And Technology, December , 2002)
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Abstract:
It is important that long superconducting tape must have
desired strain tolerance (less reduction of Jc with applied strains) and
stress tolerance (less reduction of JC in applied stresses) for its use as
coils and magnets. Ag addition to the BPSCCO system has many
advantages with its physical and chemical inertness to the system,
reduces the processing temperature, and promotes the grain growth,
grain alignment and connectivity. All these not only enhance the
critical current density of the tapes but also improve the mechanical
properties. But the published results show very much scattering on the
type of Ag additive to be selected, method of addition and its optimum
percentage. Also there are some negative reports in this regard. The
present work has been undertaken to study the effect of silver addition
in different forms (Ag powder, Ag2O, AgNO3) on the superconducting
and mechanical properties of (Bi,Pb)-2223/Ag tapes and to find out a
suitable form of Ag additive and its optimum percentage to have better
superconducting and mechanical properties. Also it is the aim of the
present work is to optimise the process parameters needed to prepare
(Bi,Pb)-2223/Ag multifilamentary tapes of length ~ 12 m in solenoid
and pancake coil forms with good critical current density and
homogeneity of J C along the length of the tapes.
Description:
Department of physics, Cochin University of Science And Technology
Radhakrishnan, M K; Dr.Joy, George(Cochin University of Science And Technology, February , 1981)
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Abstract:
The Thesis consist of the study of the electrical properties of antimony trisulphide films and the electrical behaviour of different metal contacts to antimony trisulphide films. Since the thermal evapouration of the compound antimony trisulphide as such mayresult in nonstoichiometric compound films , sb2s3 films in the present work were mostly prepared by the three temperature method ,keeping the substrate at different temperature ranging from 3031 to 4231 and evapourating antimony and sulphur simultaneously from separate sources.
Description:
Department of Physics, Cochin University of Science And Technology
Urmila, K. S; Dr. Pradeep, B.(Cochin University of Science and Technology, August 6, 2016)
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Abstract:
The use of energy in our day to day life has grown exponentially and
conserving energy to meet the world’s escalating energy demands is the need of
the hour. During the past decade there is a heightened awareness all over the
world that the production costs of energy from coal, oil and natural gas is
increasingly higher and at the same time the energy technologies involving their
use are contributing to a serious rise in the greenhouse gases in the environment
and a consequent global warming. As a result, more attention is focused on the
utilization of clean energy technologies, especially solar energy which has a
great potential to meet a large fraction of world’s energy demands using
photovoltaics (PV). The heart of the PV system that efficiently convert sunlight
directly into electricity through photovoltaic effect is the solar cell - originally
developed for space applications in the 1950s, are now used in consumer
products, mounted on roofs of houses or assembled into large power stations.
Joseph, K S; Dr.George, Joy(Cochin University of Science and Technology, 1983)
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Abstract:
In this thesis the preparation and properties of thin films of certain semiconducting sulphides (sulphides of tin, copper and indium) are reported. As single source evaporation does not yield satisfactory films of these compounds for a variety of reasons, reactive evaporation of the metal in a sulphur atmosphere has been used for film preparation. It was found that for each metal sulphide a stoichimetric interval of fluxes and substrate temperature exists for the formation of the compound in accordance with the analysis of Guenther. The first chapter of the thesis gives a resume of the basic principles of semiconductor physics relevant to the work reported here. In the second chapter is discussed in detail the reactive evaporation techniques like ordinary reactive evaporation, activated reactive evaporation and reactive ion plating. Third chapter deals with the experimental techniques used in this study for film preparation and characterization. In the next seven chapters is discussed the preparation and properties of the compound films studied. The last chapter gives a general theory of the formation of compound films in various deposition techniques in terms of the kinetic energy of the film forming particles. It must be mentioned here that this is of fundamental importance to thin film deposition and is virtually untouched in the literature
Description:
Department of Physics, Cochin University of Science and Technology
Benoy, M D; Dr.Pradeep, B(Cochin University of Science and Technology, May 7, 2001)
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Abstract:
The investigation of physical properties of matter has progressed so much
during the last hundred years. Today physics is divided in to a large distinct group
of special branches. These branches are distinguished by the particular area
studied, method of investigation and so on. An independent and important branch
that has developed is the physics ofthin films.Any object in solid or liquid form with one of its dimensions very much
smaller than that of the other two may be called a thin film. It is having only one
common property, namely, one of their dimensions is very small, though all their
physical properties may be different. Thin layers of oil, floating on the surface of
water, with their fascinating colours, have attracted men’s curiosity from time
immemorial. The earliest application of thin films was the protective coatings in
the form of paints. A thin layer of tin has been used from ancient times to protect
copper utensils from corrosion. Indium thin films are used in certain applications
on account of their good lubricating property. Relay contacts are coated with thin
films of rare earth metals in order to prevent burning due to arcing. Hard coatings
are also available using diamond like carbon (i-carbon). The basic properties of
thin films are of considerable interest because of their potential applications in
various fields of science and technology
Description:
Department of Physics, Cochin University of Science And
Technology
Binoy, Paul; Dr.Girijavallabhan,C P(Cochin University of Science & Technology, February , 2004)
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Abstract:
Nonlinear optical processes in organic compounds have attracted considerable interest in the field of science and technology because of their compelling technological promises in fields of optical communication,computing,switching and signal processing.As a result of the synthesis of novel organic compounds with varying degree of nonlinear optical strength, many practical devices based on these are getting realised giving new theoretical insights into the nonolinear optical behaviour of materials.Organic compounds like phthalocyanines and porphyrins have evoked great deal of interest in the field of photonic technology.The present thesis describes the results obtained from the investigations carried out on the nonlinear optical properties of certain organo-metallic compounds using Z-Scan and DFWM techniques.
Description:
International School of Photonics,
Cochin University of Science & Technology