Raju, John K; Dr.Kuriakose, V C(Cochin University of Science and Technology, January 6, 1999)
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Abstract:
The thesis deals with the study of super conducting properties of layered cuprates
within the frame work of a modified Lawrence-Doniach (LD) model. The thesis is
organized in seven chapters. Chapter I is a survey of the phenomena and theories
of conventional superconductivity which can serve as a springboard for launching
the study of the new class of oxide superconductors and it also includes a
chronological description of the efforts made to overcome the temperature barrier.
Chapter II deals with the structure and properties of the copper oxide superconductors
and also the experimental constraints on the theories of high te:::nperature
superconductivity. A modified Lawrence-Doniach type of phenomenological model
which forms the basis of the presnt study is also discussed. In chapter III~ the temperature
dependence of the upper critical field both parallel and perpendicular to
the layers is determined and the results are compared with d.c. magnetization
measurements on different superconducting compoilllds. The temperature and
angular dependence of the lower critical field both parallel and perpendicular to
the layers is also discussed. Chapters IV, V and VI deal with thermal fluctuation
effects on superconducting properties. Fluctuation specific heat is studied in chapter
IV. Paraconductivity both parallel and perpendicular to the layers is discussed
in chapter V. Fluctuation diamagnetism is dealt with in chapter VI. Dimensional
cross over in the fluctuation regime of all these quantities is also discussed. Chapter
VII gives a summary of the results and the conclusions arrived at.
Description:
Department of Physics, Cochin University of Science and Technology
Ajith,G Nair; Damodaran,K T(Department of Marine Geology and Geophysics, School of Marine Sciences, 2001)
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Abstract:
The present work attempts to trace the variation in the physical and chemical behavior of ilmenite, since its release from country rocks and subsequent transportation to the coast through the progressive weathering environments of laterite, sedimentary rocks, rivers and estuarine systems. Since the hinterland of the study area consists of crystalline and sedimentary rocks and their weathered forms (laterites), the contribution of each lithological system to the beach placer is attempted. The results of the study show that the most magnetic fraction contains more content of altered phases than the relatively unweathered fractions. The fractions separated above 0.35A define a high grade of ilmenite ore enriched in Ti content. The lattice volume generally decreases with alteration. The magnetic studies revels that the Chavara ilmenite are found to be made up to low magnetic crops with about 46% of the bulk ilmenite constituted by fractions separated at above 0.35A. In the Manavalakurichi ilmenite on the other hand, around 91% of the beach ilmenite is made of fractions separated at or below 0.3A
Mohandass, C; Dr.Chandrasekaran,M(Cochin University of Science and Technology, July 29, 1992)
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Abstract:
Cell immnhilizatinn technology in a rapidly expanding arna in the endeavour of microbial fnrmentatiwn.During the lnmt 15 years anveral prnceafinn have been developed and more are in developmental atage of approaching commercial utilizatinn.In the present programme it was planned to develop an optimized process for the innobilization of alpha amylase producing Bacillus polymyxa (CBTB 25) an isolate obtained from Cochin University campus primarily for the production of alpha-amylase.Optimal concentration of support material that attributaa stability and maximal activity to the immobilized cell beads was determined using different concentrations of sodium aliginate as support and estimation of amylase production.An overeall assessment of the data obtained for the various studies conducted denotes that immobilized cells synthesize alpha-amylase at comparable rates with free cells and produce reducing sugara at a higher level than free cells.Results indicated that both phosphate and citrate buffers could be used for disrupting the immobilized beads since they enforced maximal release of cells through leaching from the beads within one hour.On comparative analysis it was observed that immobilized cells could synthesize alpha amylase at similar levels with free cells of B.polymyxa.On Co-immobilization of B.Polymyxa with S.cerevisiae,the co-immobilizate beads could effeciently convert starch directly to ethanol with a yield of 14.8% at 1 : 2 ratio.
Description:
Division of Botechnology, Department of science, Cochin University of Science and Technology
Purushan, K.S; Dr.Sakthivel, M(Marine Products Export Development Authority, December , 1992)
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Abstract:
The thesis entitled "Studies on improved practices of prawn farming for higher production in central Kerala"
prepared by the author describes various practices prevailing in the study area in order to elucidate their relative merits. The study on
semi-intensive farming at Mundapuram, Kannur was also carried out
and included in the thesis for comparison.The author felt it important to make a
critical study of the existing culture practices in the central Kerala,
a region where it has been existing since time immemorial.Careful analysis of data accrued by the author has helped
him to identify strength, weakness, opportunities and threats
confronting the shrimp farming.
As a result it was possible to evolve an appropriate
management technology taking into consideration the various ecological
(location specific), social and economical conditions prevalent in the
vast study area.
Vaheed, Yavari; Dr.Thomas, M M(Cochin University of Science and Technology, December , 1994)
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Abstract:
The Indian edible oyster Crassostrea madrasensis (Preston) is known to be a highly suitable candidate species for culture. Though Q, madrasensis has been subjected to intensive research, there has been no significant attempt to culture this oyster commercially. One major reason for the lack of interest in oyster culture could be the disparity in growth, survival and production reported by earlier workersf from different regions along the Indian coast. Greater predictability of production can create confidence and encourage entrepreneurs interested
in oyster culture. The present study, which is a detailed investigation on the influence of various environmental variables on growth and reproduction of Q, madrasensis, is not confined to the impact of only hydrological parameters but is also extended to study the effect of different degrees of aerial exposure on growth and survival. The main objective of the study is to develop a background for subsequent development of a site suitability index for culture of Q, madrasensis along the Indian coast. Two sets of experiments were conducted during the present study. Details of the experiments are presented in the thesis under two major chapters comprising four sections each. Each chapter has a separate introduction, materials and methods, results and discussion.
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Maya,K S; Dr.Rani,Joseph(Cochin University of Science & Technology, July , 2007)
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Abstract:
Precipitated silica is the most promising alternative for carbon black in tyre tread compounds due to its improved performance in terms of rolling resistance and wet grip.But its poor processability is a serious limitation to its commercial application.This thesis suggests a novel route for the incorporation of silica in rubbers,i.e.,precipitation of silica in rubber latex followed by coagulation of the latex to get rubber-silica maseterbatch.Composites with in situ precipitated silica showed improved processability and mechanical properties,when compared to conventional silica composites.
Description:
Department of Polymer Science and Rubber
Technology, Cochin University of Science and Technology
Sreelatha, K S; Dr.Babu, Joseph K(Cochin University of Science And Technology, June , 1990)
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Abstract:
Usually typical dynamical systems are non integrable. But
few systems of practical interest are integrable. The soliton concept is a
sophisticated mathematical construct based on the integrability of a class ol'
nonlinear differential equations. An important feature in the clevelopment.
of the theory of solitons and of complete integrability has been the interplay
between mathematics and physics. Every integrable system has a lo11g list
of special properties that hold for integrable equations and only for them.
Actually there is no specific definition for integrability that is suitable for all cases.
.There exist several integrable partial clillerential equations( pdes)
which can be derived using physically meaningful asymptotic teclmiques
from a very large class of pdes. It has been established that many 110nlinear
wa.ve equations have solutions of the soliton type and the theory of
solitons has found applications in many areas of science. Among these,
well-known equations are Korteweg de-Vries(KdV), modified KclV, Nonlinear
Schr6dinger(NLS), sine Gordon(SG) etc..These are completely integrable
systems. Since a small change in the governing nonlinear prle may cause the
destruction of the integrability of the system, it is interesting to study the
effect of small perturbations in these equations. This is the motivation of the
present work.
Description:
Department of physics, Cochin University of Science And Technology
Resmi, Varghese; Dr.Lakshmy, B(Cochin University of Science And Technology, August 29, 2013)
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Abstract:
In this thesis, certain continuous time inventory problems with positive
service time under local purchase guided by N/T-policy are analysed. In
most of the cases analysed, we arrive at stochastic decomposition of system
states, that is, the joint distribution of the system states is obtained as the
product of marginal distributions of the components.
The thesis is divided into ve chapters
Description:
Department of Mathematics
Cochin University of Science and Technology
Shylaraj, K S; Dr.Chandrasekaran,M(Cochin University of Science And Technology, August 27, 1998)
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Abstract:
In the light of the very huge demand for natural ephedrine and
pseudoephidrine, a search for an angiosperm plant containing the alkaloid ephedrine
was made and could locate Sida spp. of malvaceae family. Sida is a large genus of,
herbs and shrubs distributed throughout the tropics. About a dozen species occur in
India. The medicinally important species known are S.rhombrfolia S.cordata and
S.spinosa (Anon, 1972). Among the various species, S.rh0mbIfolia is the most widely
used one in the traditional system of medicine. An attempt was made in the present
study to develop an ideal bioprocess for the in vitro production of ephedrine from the
cell culture system of Sida rhombrfolia Linn. ssp. retusa. The callus and suspension
culture were initiated and attempts were made to enhance the yield positively by
employing various strategies like mutagenesis, immobilization and addition of
precursors, elicitors and penneabilizing agents.
Description:
Department of Biotechnology
Cochin University of Science and Technology
Manjusha, S; Dr.Sarita,Bhat G(Cochin University of Science and Technology, December , 2006)
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Abstract:
While the seriousness of the problem of antibiotic resistance is now
recognized, the complex web of resistance linking humans, animals, and the
environment is getting realized. More often, antibiotics are used as a preventive
measure against diseases. Antibiotic use for agriculture leads to the increased
resistance in the environment since antibiotics are inevitable element during
agriculture/aquaculture and antibiotic residues are excreted as waste that is frequently
spread onto farmland as organic fertilizer. Fecal bacteria survive long periods in the
environment and spread through runoff into groundwater, rivers, and marine
ecosystems.However, horizontal gene transfer occurs in the animals and guts of humans and
in a variety of ecosystems, creating a pool of resistance in the rice fields and open
waters. Even if people are not in direct contact with resistant disease through food
animals, there are chances of contact with resistant fecal pathogens from the
environment. Additionally, pathogens that are autochthonous to the environment can
acquire resistance genes from the environment. Our study revealed that autochthonous
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bacteria Vibrio spp gained antibiotic resistance in the environment. Further, it was
evident that horizontal gene transfer occurs in Vibrio by means of plasmids, which
further augments the gravity of the problem. Non-pathogenic bacteria may also
acquire resistance genes and serve as a continuing source of resistance for other
bacteria, both in the environment, and in the human gut. As the effectiveness of
antibiotics for medical applications decline, the indiscriminate use of in aquaculture
and in humans can have disastrous conditions in future due to horizontal gene transfer
and the spread of resistant organisms: We must recognize and deal with the threat
posed by overuse of antibiotics.
Description:
Department of Biotechnology,
Cochin University of Science and Technology
Sona, A; Dr. Mukundan, M K(Central Institute of Fisheries Technology, July , 2004)
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Abstract:
In the attempt to find out catalytic potency and properties of the endoglucanase
of green mussel, it could be highlighted that the enzyme is efficient in degrading
carboxymethylcellulose to reducing sugars. The immobilized enzyme will find
applications in the food industry, paper and pulp industry, wood preservation,
alcohol and pharmaceutical industry.The purification method employed i.e. Sephadex G100 chromatography
employing affinity and exclusion principles simplify the purification procedure.Addition of Mg2+ and Co2+ at 10mM concentrations enhances endoglucanase
activity of green mussel.The immobilized endoglucanase can be used for deinking mixed office waste
paper. The endoglucanase if supplemented with exoglucanase and B-glucosidase
under appropriate conditions would help in the recycling of paper.
Seema Nair,P; Surendran,P K(Microbiology, Fermentation and Biotechnology Division Central Institute of Fisheries Technology, Faculty of Marine Sciences, November , 2000)
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Abstract:
In this study, an attempt has been made to gather enough information regarding lactic acid bacteria from fish and shellfish of tropical regions. The occurrence and distribution of lactic acid bacteria in fresh and frozen marine fish and shellfish, farmed fish and shellfish, cured and pickled fish and shellfish have been investigated. Lactic Acid Bacteria (LAB) have for centuries been responsible for the fermentative preservation of many foods. They are used to retard spoilage and preserve foods through natural fermentations. They have found commercial applications as
starter cultures in the dairy, baking, meat, fish, and vegetable and alcoholic beverage
industries. They are industrially important organisms recognized for their fermentative
ability as well as their nutritional benefits. These organisms produce various compounds
such as organic acids, diacetyl, hydrogen peroxide and bacteriocins or bactericidal
proteins during lactic fermentations.Biopreservation of foods using bacteriocin producing LAB cultures is becoming widely used. The antimicrobial effect of bacteriocins and other compounds
produced during fermentation of carbohydrates are well known to inhibit the growth of
certain food spoiling bacteria as well as a limited group of food poisoning and pathogenic bacteria LAB like Lactobacillus plantarum are widely used as starter cultures for the
Production of fish ensilage. The present study is the first quantitative and qualitative study on the
occurrence and distribution of lactic acid bacteria in fresh and frozen fish and prawn. It
is concluded that Lactobacillus plantaruni was the predominant lactobacillus species in fresh and frozen fish and shellfish. The ability of selected Lactobacillus cultures to grow at low temperatures, high salt content, produce bacteriocins, rapidly ferment sugars and decrease the pH make them potential candidates for biopreservation of fish and shellfish.