Balarama Kaimal,S; Dr. Paulose, C S(Cochin University of Science & Technology, July , 2005)
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Abstract:
The present study demonstrate the functional alterations of the GABAA and GABAB
receptors and the gene expression during the regeneration of pancreas following
partial pancreatectomy. The role of these receptors in insulin secretion and
pancreatic DNA synthesis using the specific agonists and antagonists also are studied
in vitro. The alterations of GABAA and GABAR receptor function and gene
expression in the brain stem, crebellum and hypothalamus play an important role in
the sympathetic regulation of insulin secretion during pancreatic regeneration.
Previous studies have given much information linking functional interaction between
GABA and the peripheral nervous system. The involvement of specific receptor
subtypes functional regulation during pancreatic regeneration has not given emphasis
and research in this area seems to be scarce. We have observed a decreased GABA
content, down regulation of GABAA receptors and an up regulation of GABAB
receptors in the cerebral cortex, brain stem and hypothalamus. Real Time-PCR
analysis confirmed the receptor data in the brain regions. These alterations in the
GABAA and GABAB receptors of the brain are suggested to govern the regenerative
response and growth regulation of the pancreas through sympathetic innervation. In
addition, receptor binding studies and Real Time-PCR analysis revealed that during
pancreatic regeneration GABAA receptors were down regulated and GABAB
receptors were up regulated in pancreatic islets. This suggests an inhibitory role for
GABAA receptors in islet cell proliferation i.e., the down regulation of this receptor
facilitates proliferation. Insulin secretion study during 1 hour showed GABA has
inhibited the insulin secretion in a dose dependent manner in normal and
hyperglycaemic conditions. Bicuculline did not antagonize this effect. GABAA
agonist, muscimol inhibited glucose stimulated insulin secretion from pancreatic
islets except in the lowest concentration of 1O-9M in presence of 4mM glucose.Musclmol enhanced insulin secretion at 10-7 and 10-4M muscimol in presence of
20mM glucose- 4mM glucose represents normal and 20mM represent
hyperglycaemic conditions. GABAB agonist, baclofen also inhibited glucose induced
insulin secretion and enhanced at the concentration of 1O-5M at 4mM glucose and at
10-9M baclofen in presence of 20mM glucose. This shows a differential control of
the GABAA and GABAB receptors over insulin release from the pancreatic islets.
During 24 hours in vitro insulin secretion study it showed that low concentration of
GABA has inhibited glucose stimulated insulin secretion from pancreatic islets.
Muscimol, the GABAA agonist, inhibited the insulin secretion but, gave an enhanced
secretion of insulin in presence of 4mM glucose at 10-7
, 10-5 and 1O-4M muscimol.
But in presence of 20mM glucose muscimol significantly inhibited the insulin
secretion. GABAB agonist, baclofen also inhibited glucose induced insulin secretion
in presence of both 4mM and 20mM glucose. This shows the inhibitory role of
GABA and its specific receptor subtypes over insulin synthesis from pancreatic bete-islets.
In vitro DNA synthesis studies showed that activation of GABAA receptor by
adding muscimol, a specific agonist, inhibited islet DNA synthesis. Also, the
addition of baclofen, a specific agonist of GABAB receptor resulted in the stimulation
of DNA synthesis.Thus the brain and pancreatic GABAA and GABAB receptor
gene expression differentially regulates pancreatic insulin secretion and islet cell
proliferation during pancreatic regeneration. This will have immense clinical
significance in therapeutic applications in the management of Diabetes mellitus.
Description:
Department of Biotechnology,
Cochin University of Science and Technology
Jobin, Mathew; Dr. Paulose, C S(Cochin University of Science and Technology, March 11, 2010)
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Abstract:
The research work which was carried out to characterization of wastes from natural rubber and rubber wood processing industries and their utilization for biomethanation. Environmental contamination is an inevitable consequence of human activity. The liquid and solid wastes from natural rubber based industries were: characterized and their use for the production of biogas investigated with a view to conserve conventional energy, and to mitigate environmental degradation.Rubber tree (flevea brasiliensis Muell. Arg.), is the most important commercial source of natural rubber and in india. Recently, pollution from the rubber processing factories has become very serious due to the introduction of modern methods and centralized group processing practices.The possibility of the use of spent slurry as organic manure is discussed.l0 percent level of PSD, the activity of cellulolytic, acid producing,proteolytic, lipolytic and methanogenic bacteria were more in the middle stage of methanogenesis.the liquid wastes from rubber processing used as diluents in combination with PSD, SPE promoted more biogas production with high methane content in the gas.The factors that favour methane production like TS, VS, cellulose and hemicellulose degradation were favoured in this treatment which led to higher methane biogenesis.The results further highlight ways and means to use agricultural wastes as alternative sources of energy.
Description:
Department of Biotechnology, Cochin University of Science and Technology
Shilpa, Joy; Dr. Paulose, C S(Cochin University of Science And Technology, July , 2013)
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Abstract:
Nanoparticulate drug delivery systems provide wide opportunities for
solving problems associated with drug stability or disease states and create great
expectations in the area of drug delivery (Bosselmann & Williams, 2012).
Nanotechnology, in a simple way, explains the technology that deals with one
billionth of a meter scale (Ochekpe, et al., 2009). Fewer side effects, poor
bioavailability, absorption at intestine, solubility, specific delivery to site of action
with good pharmacological efficiency, slow release, degradation of drug and
effective therapeutic outcome, are the major challenges faced by most of the drug
delivery systems. To a great extent, biopolymer coated drug delivery systems
coupled with nanotechnology alleviate the major drawbacks of the common
delivery methods. Chitosan, deacetylated chitin, is a copolymer of β-(1, 4) linked
glucosamine (deacetylated unit) and N- acetyl glucosamine (acetylated unit)
(Radhakumary et al., 2005). Chitosan is biodegradable, non-toxic and bio
compatible. Owing to the removal of acetyl moieties that are present in the amine
functional groups of chitin, chitosan is readily soluble in aqueous acidic solution.
The solubilisation occurs through the protonation of amino groups on the C-2
position of D-glucosamine residues whereby polysaccharide is converted into
polycation in acidic media. Chitosan interacts with many active compounds due to
the presence of amine group in it. The presence of this active amine group in
chitosan was exploited for the interaction with the active molecules in the present
study. Nanoparticles of chitosan coupled drugs are utilized for drug delivery in
eye, brain, liver, cancer tissues, treatment of spinal cord injury and infections
(Sharma et al., 2007; Li, et a., 2009; Paolicelli et al., 2009; Cho et al., 2010). To
deliver drugs directly to the intended site of action and to improve
pharmacological efficiency by minimizing undesired side effects elsewhere in the
body and decrease the long-term use of many drugs, polymeric drug delivery
systems can be used (Thatte et al., 2005).
Description:
Department of Biotechnology, Cochin University of Science and Technology
Biju,M P; Paulose,C S(Department of Biotechnology, 2000)
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Abstract:
The present thesis is an attempt to understand the role of GABA, GABAA and GABAB receptors in the regulation of liver cell proliferation using in vivo and in vitro models. The work also focuses on the brain GABAergic changes associated with normal and neoplastic cell growth in liver and to delineate its regulatory function. The investigation of mechanisms involving mitogenic models without cell necrosis may contribute our knowledge about both on cell growth, carcinogenesis, liver pathology and treatment. Objectives of the present study are, to induce controlled liver cell proliferation by partial hepatectomy and lead nitrate administration and uncontrolled cell proliferation by N-nitrosodiethylamine treatment in male Wistar rats, the changes in the content of GABA, GABAA,GABAB in various rat brain regions. To study the GABAA and GABAB receptor changes in brain stem, hypothalamus, cerebellum and cerebral cortex during the active cortex during the period of active DNA synthesis in liver of different experimental groups. The changes in GABAA and GABAB receptor function of the brain stem, hypothalamus and cerebellum play an important role sympathetic regulation of cell proliferation and neoplastic growth in liver. The decrease in GABA content in brain stem, hypothalamus and cerebellum during regeneration and neoplasia in liver. The time course of brain GABAergic changes was closely correlated with that of heptic DNA synthesis. The functional significance of these changes was further explored by studying the changes in GABAA and GABAB receptors in brain.
Anju, T R; Dr. Paulose, C S(Cochin University of Science and Technology, September , 2010)
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Abstract:
The present study was designed to investigate the protective effect of
glucose, oxygen and epinephrine resuscitation on impairment in the functional role
of GABAergic, serotonergic, muscarinic receptors, PLC, BAX, SOD, CAT and
GPx expression in the brain regions of hypoxia induced neonatal rats. Also, the
role of hormones - Triiodothyronine (T3) and insulin, second messengers –
cAMP, cGMP and IP3 and transcription factors – HIF and CREB in the regulation
of neonatal hypoxia and its resuscitation methods were studied. Behavioural
studies were conducted to evaluate the motor function and cognitive deficit in one
month old control and experimental rats. The efficient and timely supplementation
of glucose plays a crucial role in correcting the molecular changes due to hypoxia,
oxygen and epinephrine. The sequence of glucose, epinephrine and oxygen
administration at the molecular level is an important aspect of the study. The
additive neuronal damage effect due to oxygen and epinephrine treatment is
another important observation. The corrective measures by initial supply of
glucose to hypoxic neonatal rats showed from the molecular study when brought
to practice will lead to healthy intellectual capacity during the later developmental
stages, which has immense clinical significance in neonatal care.
Description:
Department of Biotechnology,
Cochin University of Science and Technology
Sebastian, C A; Dr.Chandrasekharan Pillai, K N(Cochin University of Science and Technology, April 20, 1995)
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Abstract:
The present work deals with the Gender discrimination in the law of divorce and succession among christians.Inquiries Into the personal laws bereft of the historical develcpment of the concerned communities will be extremely inadequate as they may not help the researcher to Identify the laws' real source.In this view, the origin and development of Christian law In india has not so far been adequately gone into. Keeping In view the Importance of such a study calling for an exploration of the origin and development of the Christian community and its branching out In india as a prelude to the inqury into the Christian laws, the history of the conmunity in india was examined and the present study IndIcates that christianity In india has a diverse origin in dIfferent parts of India.And this diversity has resulted in the development of different systems of personal law for different sects among them. At present Christians in India constitute a minority but their numerical strength is not negligible. Yet they have not been able to act as an Influential group either socially or politically.The social changes and developments that swept away the community of its feet have overturned the position and the liberals in the community inspired by the changes elsewhere could bring in some statute law to govern the arena traditionally held by the customs.The history of reception of canon law concepts In different parts of India throws some light on the differences In the personal laws applicable to Christians In India.
Description:
Department of Law, Cochin University of Science and Technology.
Lalithabhai,K N; Sankaranarayanan,K C(Department of Applied Economics, Faculty of Social Sciences, 2003)
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Abstract:
Women participating in work outside home and the resultant change in Labour market structure placeing female labour as a strong component were breakthrough of twentieth centry. The major share of women labourers in India is crowding in agriculture, household industries and other traditional sectors. Shift in cropping pattern has adverse impacts on female labour. Female labour lost opportunities in the labour market this has adverse impact on family consumption. The study is directed to investigate the impact of female labour saving shift in cropping on female labour force participation and the resultant change in household consumption pattern the specific objectives this study are impact of change in the cropping pattern on employment, change female employment, family consumption pattern and changing situations of womenlabour in agriculture sector.
Swapna,T S; Padma, Nambisan(Department of Biotechnology, March , 2000)
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Abstract:
The study deals with the generation of variability for salt tolerance in rice using tissue culture techniques. Rice is the staple food of more than half of the world’s population. The management of drought, salinity and acidity in soils are all energy intensive agricultural practices. The Genetic variability is the basis of crop improvement. Somaclonal and androclonal variation can be effectively used for this purpose. In the present study, eight isozymes were studied and esterase and isocitric dehydrogenase was found to have varietal specific, developmental stage specific and stress specific banding pattern in rice. Under salt stress thickness of bands and enzyme activity showed changes. Pokkali, a moderately salt tolerant variety, had a specific band 7, which was present only in this variety and showed slight changes under stress. This band was faint in tillering and flowering stage .Based on the results obtained in the present study it is suggested that esterase could possibly be used as an isozyme marker for salt tolerance in rice. Varietal differences and stage specific variations could be detected using esterase and isocitric dehydrogenase . Moreover somaclonal and androclonal variation could be effectively detected using isozyme markers.
Jeena, N S; Dr.Gopalakrishnan, A(Cochin University of Science And Technology, May 23, 2013)
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Abstract:
The management of exploited species requires the identification of
demographically isolated populations that can be considered as independent
management units (MUs), failuring in which can lead to over -fishing and
depletion of less productive stocks. By characterizing the distribution of genetic
variation, population sub structuring can be detected and the degree of
connectivity among populations can be estimated. The genetic variation can be
observed using identified molecular markers of both nuclear and mitochondrial
origin. Hence, the present work was undertaken to study the genetic diversity
and population/stock structure in P. homarus homarus and T. unimaculatus
from different landing centres along the Indian coast using nuclear (RAPD) and
mitochondrial DNA marker tools which will help towards developing
management strategies for management and conservation of these declining
resources.To make consistent conservation and fisheries management decisions,
accurate species identifications are needed. It is also suggested that it is not
always desirable to rely on a single sequence for taxonomic identification.
Thus, the feasibility of using partial sequences of additional mitochondrial
genes like 16SrRNA, 12SrRNA and nuclear 18SrRNA has also been explored
in our study. Phylogenies provide a sound foundation for establishing
taxonomy. The present work also attempts to reconstruct the phylogeny of
eleven species of commercially important lobsters from the Indian EEZ using
molecular markers
Description:
National Bureau of
Fish Genetic Resources (NBFGR) Cochin Unit, Central Marine Fisheries Research
Institute, Cochin
The thesis deals with the results of the study of the population characteristics of the marine penaeid prawn, Penaeus monodon from South India. The present findings on the morphometric and biochemical genetic structure support the hypothesis that the populations of P.monodon of South India have homogeneous stock structure. To the contrary, the significantly different random amplified polymorphic DNA (RAPD) profiles in samples of Kochi and Chennai support the hypothesis that east and west cost populations of P.monodon are separate stocks.
Manju, Nair P; Dr. Sujatha, C.H(Cochin University of Science & Technology, June , 2014)
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Abstract:
Geochemical composition is a set of data for predicting the climatic condition existing in an ecosystem. Both the surficial and core sediment geochemistry are helpful in monitoring, assessing and evaluating the marine environment. The aim of the research work is to assess the relationship between the biogeochemical constituents in the Cochin Estuarine System (CES), their modifications after a long period of anoxia and also to identify the various processes which control the sediment composition in this region, through a multivariate statistical approach. Therefore the study of present core sediment geochemistry has a critical role in unraveling the benchmark of their characterization. Sediment cores from four prominent zones of CES were examined for various biogeochemical aspects. The results have served as rejuvenating records for the prediction of core sediment status prevailing in the CES
Reji,Srinivas; Sajan,K(Department of Marine Geology and Geophysics, School of marine Sciences, 2002)
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Abstract:
In this study, an attempt has been made to find the textural, geochemical, sedimentological characteristics of sediments and water phases of the kayamkulam estuary located in the Southwest coast of Kerala, besides the impact of gas based thermal power plant located at the northern part of the estuary. Estuaries are an important stage in the transport of the solid weathering product of the earth’s crust. These weathered products or sediments are complex mixtures of a number of solid phases that may include clays, silica, organic matter, metal oxides, carbonates, sulfides and a number of minerals. Studies on the aquatic systems revealed the fact that it posses severe ecological impairments due to heavy discharge of sediments from 44 rivers, the continued disposal of pollutants rich materials from industries, sewage channels, agricultural areas and retting yards
Hariharan,G N; Nambiar,C G(Department of Marine Geology & Geophysics, School of Marine Sciences, 2001)
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Abstract:
The present work deals with the texture, mineralogy and geochemistry of bedload sediments of the main stream of the Chaliyar basin, a typical small drainage system of the tropics enjoying heavy rain fall and moderate climate, located essentially in the Northern Kerala and flowing over the crystalline rocks (and their laterized duricrust) of the South Indian granulite terrain. As the Chaliyar is the major river draining the Wynad Gold Fields and is known for its placer gold occurrences, the thesis gives special emphasize on understanding the nature and distribution of detrital gold in sediments of the basin, while attempting to infer the provenance characteristics and factors involved in the evolution of sediments in general. Minerologically the chaliyar basin sands are quartzose. The quartz and feldspar contents in the coarse sand fraction of the basin range from 64 to 86% and 2 to 16% respectively. The Q/F ration ranges from 4 to 38 with a slight decrease in the lower reaches. Other minerals present include, hornblende, pyroxene and heavy minerals like opaques, garnet, rutile, biotite, spene, silliminite, zircon, apatite and monazite some of which are seen as inclusions in quartz. The major element composition of Chaliyar bedload sediments in the main channel and the headwater tributaries is related to the mineralogical and textual characteristics of sediments.
Soney Kurien, P; Dr.Nambiar,C G(Cochin University Of Science And Technology, May 2, 2000)
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Abstract:
This report deals essentially with the geochemistry and petrogenesis
of Perinthatta anorthosite. The work also addresses the geological setting
of the pluton in terms of its field relationships and petrography and the
structure and metamorphism of the region and examines its relation with
the associated plutons. For the sake of convenience, the thesis is divided
into six chapters
Description:
Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin
University of Science and Technology
Siby,Varghese; Chandramohanakumar, N(National Institute of Oceanography & CUSAT, 2003)
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Abstract:
Rare earth elements have occupied an important role in marine geochemical research, particularly as used in the format of REE abundance patterns to describe the geochemical pathways in marine sedimentation and authigenesis. This study concentrates on the distribution pattern of Rare earth elements in the sediments, behavior of Eu and Ce with respect to their occurrence in multiple oxidation states. It also concentrate the depth wise variation of sediment REEs from near shore areas (30m) to deeper depths 200m) in the Arabian Sea. It includes the downcore variation of REEs and other trace elements in the sediment cores and a comparison between the REE distributions of Arabian Sea sediment with the sediments of Andaman Sea. The study gives a general introduction regarding the importance of RRE studies, its occurrence and abundance, electronic configuration, lanthanide contraction, oxidations states and REE supply to the ocean, seawater and sediments.
Laluraj, C M; Dr.Muraleedharan Nair, S(Cochin University of Science and Technology, February , 2009)
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Abstract:
The metals present in the surface sediments have high demand on a
global perspective, and the main reservoir of these elements is believed to be
the ocean floor. A lot of studies on metals are going on throughout the world
for its quantification and exploitation. Even though, some preliminary
attempts have been made in selected areas for the quantitative study of
metals in the western continental shelf of India, no comprehensive work has
been reported so far. The importance of this study also lies on the fact that
there has not been a proper evaluation of the impact of the Great Tsunami of
2004 on the coastal areas of the south India. In View of this, an attempt has
been made to address the seasonal distribution, behavior and mechanisms
which control the deposition of metals in the sediments of the western
continental shelf and Cochin Estuary, an annex to this coastal marine region.Surface sediment samples were collected seasonally from two
subenvironemnts of southwest coast of India, (continental shelf of Kerala and
Cochin estuarine system), to estimate the seasonal distribution and geochemical
behavior of non-transition, transition, rare-earth elements, Th and U. Bottom
water samples were also taken from each station, and analysed for temperature,
salinity and dissolved oxygen, hence the response of redox sensitive elements to
oxygen minimum zone can be addressed. In addition, other sedimentary
parameters such as sand, silt, clay fractions, CaCO3 and organic carbon content
were also estimated to evaluate the control factors on level of metals present in
the sediment. The study used different environmental data analysis techniques
to evaluate the distribution and behavior of elements during different seasons.
This includes environmental parameters such as elemental normalisation,
enrichment factor, element excess, cerium and europium anomalies and
authigenic uranium.
Description:
Department of Chemical Oceanography,Cochin University of Science and Technology
Lasitha, S; Dr.Radhakrishna, M(Cochin University of Science and Technology, September , 2007)
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Abstract:
This work aims to study the variation in subduction
zone geometry along and across the arc and the fault pattern within the subducting
plate. Depth of penetration as well as the dip of the Benioff zone varies considerably
along the arc which corresponds to the curvature of the fold- thrust belt which varies
from concave to convex in different sectors of the arc. The entire arc is divided into 27
segments and depth sections thus prepared are utilized to investigate the average dip
of the Benioff zone in the different parts of the entire arc, penetration depth of the
subducting lithosphere, the subduction zone geometry underlying the trench, the arctrench
gap, etc.The study also
describes how different seismogenic sources are identified in the
region, estimation of moment release rate and deformation pattern. The region is
divided into broad seismogenic belts. Based on these previous studies and seismicity
Pattern, we identified several broad distinct seismogenic belts/sources. These are l)
the Outer arc region consisting of Andaman-Nicobar islands 2) the back-arc Andaman Sea 3)The Sumatran fault zone(SFZ)4)Java onshore region termed as Jave Fault Zone(JFZ)5)Sumatran fore arc silver plate consisting of Mentawai fault(MFZ)6) The offshore java fore arc region 7)The Sunda Strait region.As the Seismicity is variable,it is difficult to demarcate individual seismogenic sources.Hence, we employed a moving window method having a window length of 3—4° and with 50%
overlapping starting from one end to the other. We succeeded in defining 4 sources
each in the Andaman fore arc and Back arc region, 9 such sources (moving windows)
in the Sumatran Fault zone (SFZ), 9 sources in the offshore SFZ region and 7 sources
in the offshore Java region. Because of the low seismicity along JFZ, it is separated
into three seismogenic sources namely West Java, Central Java and East Java. The
Sunda strait is considered as a single seismogenic source.The deformation rates for
each of the seismogenic zones have been computed. A detailed error analysis of
velocity tensors using Monte—Carlo simulation method has been carried out in order
to obtain uncertainties. The eigen values and the respective eigen vectors of the
velocity tensor are computed to analyze the actual deformation pattem for different
zones. The results obtained have been discussed in the light of regional tectonics, and
their implications in terms of geodynamics have been enumerated.ln the light of recent major earthquakes (26th December 2004 and 28th March
2005 events) and the ongoing seismic activity, we have recalculated the variation in
the crustal deformation rates prior and after these earthquakes in Andaman—Sumatra
region including the data up to 2005 and the significant results has been presented.ln this
chapter, the down going lithosphere along the subduction zone is modeled using the
free air gravity data by taking into consideration the thickness of the crustal layer, the
thickness of the subducting slab, sediment thickness, presence of volcanism, the
proximity of the continental crust etc. Here a systematic and detailed gravity
interpretation constrained by seismicity and seismic data in the Andaman arc and the
Andaman Sea region in order to delineate the crustal structure and density heterogeneities a Io nagnd across the arc and its correlation with the seismogenic behaviour is presented.
Description:
Department of Marine Geology & Geophysics,
Cochin University of Science and Technology
Santosh,Kumar Pandey; Dr.Chakravarti, R S(Cochin University of Science and Technology, June , 2010)
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Abstract:
This thesis entitled Geometric algebra and einsteins electron: Deterministic field theories .The work in this thesis clarifies an important part of Koga’s theory.Koga also developed a theory of the electron incorporating its gravitational field, using his substitutes for Einstein’s equation.The third chapter deals with the application of geometric algebra to Koga’s approach of the Dirac equation. In chapter 4 we study some aspects of the work of mendel sachs (35,36,37,).Sachs stated aim is to show how quantum mechanics is a limiting case of a general relativistic unified field theory.Chapter 5 contains a critical study and comparison of the work of Koga and Sachs. In particular, we conclude that the incorporation of Mach’s principle is not necessary in Sachs’s treatment of the Dirac equation.
Description:
Department of Mathematics, Cochin University of Science
and Technology
Arts,K Purushotham; Radhakrishna,M(Department of Marine Geology and Geophysics,School of Marine Sciences, 2002)
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Abstract:
The main objective of the present study is to model the gravity fields in terms of lithospheric structure below the western continental margin of India (WCMI) identify zones of crustal mass anomalies and attempt to infer the location of Ocean Continent transition in the Arabian Sea. In this study, the area starting from the western shield margin to the region covering the deep oceanic parts of the Arabian Sea which is bounded by Carlsberg and Cerg and Central Indian ridges in the south, eastern part of the Indus Cone in the west and falling between 630E and 800E longitudes, and 50N - 240N latitudes has been considered. The vast amount of seismic reflection and refraction data in the form of crustal velocities, basement configuration and crustal thicknesses available for the west coast as well as the eastern Arabian Sea has been utilized for this purpose
Saly, Thomas N; Dr. Hridayanathan, C(Cochin University of Science and Technology, May , 2001)
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Abstract:
The fishing industry the world over is passing through a critical situation.The landings of marine fishes seemed to have reached saturation in major fishing areas of the world.As a general rule fisheries employing fishing gear and techniques used by small scale and artisanal fishermen either from shore or from onboard small fishing craft come under small-scale fisheries.This study on gill nets of Kerala, the fishing method depended upon by maximum fishermen of the state focuses on the importance of this selective and low energy fishing method in the marine fishing sector of the state.The study opens with the conceptual framework by briefly reviewing the crisis in the marine fisheries sector. Maximum fishermen depend upon gill net, which is, an important selective and low energy fishing gear. A review of relevant literature on aspects such as material, selectivity and techno-economic efficiency together with scope and main objectives of the study form the major part of the compass of the introductory chapter.This survey provided the inputs for selection of centres. The chapter presents the basis for selection of sample centres, sample units and methodology for field and experimental study.The subject matter of the fourth chapter is a basic study on gear aterials. The weathering resistance, which is an important criterion to assess the material performance, was studied for polyamide monofilament in comparison to polyamide multifilament and polyethylene twisted monofilament.The study provides supporting evidence of oxidation and characteristic C-O stretching in polyethylene and cyclic lactam .formation and presence of OH in polyamide.The study indicates that small mesh gill netting can be encouraged as a selective fishing method in the inshore waters with restrained use of 30 and 32 mm mesh sizes. The economic efficiency was assessed using standard indices such as rate of return, internal rate of return, pay back period, fishery income, energy efficiency and factor productivity. The effect of size and cost of capital and cost of production on the economics of operation is also discussed in this chapter. It was observed that level of technology did not have direct effect on economic performance.
Description:
Industrial Fisheries,
Cochin University of
Science and Technology
Anoo Anna, Anthony; Dr.Mary,Joseph T(Cochin University of Science and Technology, October , 2011)
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Abstract:
The literature on the involvement of developing countries in trade has focused on the effects of different aspects of globalization on firms, regions and countries. The study attempts to examine how an export based industry, locallyembedded and originated on the basis of regional strengths has been inserted into the global trade framework. Though the unit of analysis is the manufacturing export firm in the region of Kannur, it represents the entire home textile export
industry from the state of Kerala, as close to 90% of fabric exports in home furnishing material, textiles for upholstery and decoration and stitched or fused, and branded made ups are from the region. From a global perspective, how developing countries face newer trade restrictions and overcome non quota barriers by firm and region specific activities within a value chain framework is a major research area, which has already contributions from the Ludhiana woolen
cluster (Tewari,1999 ) and the Tirupur cluster in India (Cawthorne, 1995). The study contributes to the value chain literature by examining the governance and upgrading as well as how firms benefit from linkages. India has a number of export oriented agglomerations or regions where firms have been serving export markets for many years. In many cases it is no longer the supply side policy actions that determine how they are able to penetrate new markets or expand existing market share. Based on this study it becomes possible to understand how the global value chain operates in these different industries to examine whether there is a danger of immiserisation of growth or low road growth
Description:
School of Management Studies, Cochin University of Science and Technology
Jayanarayanan, S; Dr. Paulose, C S(Cochin University Of Science And Technology, December 21, 2012)
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Abstract:
The present study was designed to investigate the protective effect of
curcumin and vitamin D3 in the functional regulation of glutamatergic NMDA and
AMPA receptors in streptozotocin (STZ) induced diabetic rats. Alterations in
glutamatergic neurotransmission in the brain were evaluated by analyzing the
glutamate content, glutamate receptors - NMDA and AMPA receptors binding
parameters and gene expression, GAD and GLAST gene expression.
Immunohistochemistry studies using confocal microscope were carried out to
confirm receptor density and gene expression results of NMDA and AMPA
receptors. The role of glutamatergic receptors in pancreas was studied using the
following parameters; glutamate content, GLAST expression, glutamate receptors
- NMDA and AMPA receptor binding and gene expression. Increasing evidence in
both experimental and clinical studies suggests that oxidative stress plays a major
role in the pathogenesis of diabetes. In the present study SOD assay and GPx gene
expression were done to evaluate the activity of antioxidant enzymes in the brain
regions and pancreas. NeuroD1 and Pdx1 gene expression were performed in
pancreas of experimental rats to evaluate pancreatic islet survival. Gene
expression profiles of caspase 8, Bax, and Akt in brain regions and pancreas were
studied to understand the possible mechanism behind curcumin and vitamin D3
mediated neuroprotection and islet survival. Gene expression studies of
vitamin D3 receptor localisation in the pancreas was done to understand the
mechanism of vitamin D3 in insulin secretion. Curcumin and vitamin D3 mediated
insulin secretion via Ca2+ release were studied using confocal microscope.
Description:
Department of Biotechnology
Cochin University of Science and Technology
Sosamma,Cherian; Dr.George, Philip(Cochin University of Science And Technology, May , 1984)
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Abstract:
Alpha glucan phosphorylase plays a very
significant role in glycolysis. The inhibition and
activation of this enzyme have significant effect on
the rate of glycolysis. The rate of glycolysis is
also determined by the interconversion between the
active 3 and inactive Q forms of phosphorylase by
two specific enzymes called phosphorylase phosphatase
and phosphorylase kinase. The allosteric properties
and interconversion mechanism reported for
well—studied animal muscle phosphorylases do not
fall under a general pattern. Studies using
purified phosphorylase from marine sources are scanty.
Detailed studies using specialised tissues from more
marine animals are necessary to find the factors that
control the properties and activities of the enzyme.
This thesis is an attempt in this direction. The
thesis deals with a detailed study of the control of
the phosphorylase by both allosterism and
interconversion between the g and b forms from four
different aquatic animals of different habitat. Phosphorylase frm the four different animal muscles were purified either partially or completely and the kinetic and control properties were studied.
Description:
School of marine sciences, Cochin University of Science And Technology
Suresh, M; Dr.Pillai, U T S(Cochin University of Science and Technology, April , 2012)
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Abstract:
Demand on magnesium and its alloys is increased significantly in the automotive industry because of their great potential in reducing the weight of components, thus resulting in improvement in fuel efficiency of the vehicle. To date, most of Mg products have been fabricated by casting, especially, by die-casting because of its high productivity, suitable strength, acceptable quality & dimensional accuracy and the components produced through sand, gravity and low pressure die casting are small extent. In fact, higher solidification rate is possible only in high pressure die casting, which results in finer grain size. However, achieving high cooling rate in gravity casting using sand and permanent moulds is a difficult task, which ends with a coarser grain nature and exhibit poor mechanical properties, which is an important aspect of the performance in industrial applications. Grain refinement is technologically attractive because it generally does not adversely affect ductility and toughness, contrary to most other strengthening methods. Therefore formation of fine grain structure in these castings is crucial, in order to improve the mechanical properties of these cast components.
Therefore, the present investigation is “GRAIN REFINEMENT STUDIES ON Mg AND Mg-Al BASED ALLOYS”. The primary objective of this present investigation is to study the effect of various grain refining inoculants (Al-4B, Al- 5TiB2 master alloys, Al4C3, Charcoal particles) on Pure Mg and Mg-Al alloys such as AZ31, AZ91 and study their grain refining mechanisms. The second objective of this work is to study the effect of superheating process on the grain size of AZ31, AZ91 Mg alloys with and without inoculants addition. In addition, to study the effect of grain refinement on the mechanical properties of Mg and Mg-Al alloys. The thesis is well organized with seven chapters and the details of the studies are given below in detail.
Description:
Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology (NIIST), CSIR
John Kurian,P; Radhakrishna,M(Department of Marine Geology and Geophysics, School of Marine Sciences, 2000)
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Abstract:
The primary aim of the present study is to acquire a large amount of gravity data, to prepare gravity maps and interpret the data in terms of crustal structure below the Bavali shear zone and adjacent regions of northern Kerala. The gravity modeling is basically a tool to obtain knowledge of the subsurface extension of the exposed geological units and their structural relationship with the surroundings. The study is expected to throw light on the nature of the shear zone, crustal configuration below the high-grade granulite terrain and the tectonics operating during geological times in the region. The Bavali shear is manifested in the gravity profiles by a steep gravity gradient. The gravity models indicate that the Bavali shear coincides with steep plane that separates two contrasting crustal densities extending beyond a depth of 30 km possibly down to Moho, justifying it to be a Mantle fault. It is difficult to construct a generalized model of crustal evolution in terms of its varied manifestations using only the gravity data. However, the data constrains several aspects of crustal evolution and provides insights into some of the major events.
Jomon Jacob, P; Dr.Prathapan, S(Cochin University of Science And Technology, January 30, 2013)
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Abstract:
the thesis entitled “Ground and Excited
State Electron Transfer Reaction Between a few Anthracene
Appended Tertiary Amines and Suitable Electron Acceptors”
portrays our attempts to explore the solvent, concentration and
temperature effect of the reaction between a few (anthracen-9-
yl)methanamines with electron acceptors like DMAD, DBA and
DBE. We have also studied the effect of solvent and percentage
fluorescence quenching in the photoinduced electron transfer
reactions of these ‘donor-spacer-acceptor’ systems. Finally we
look in to the intramolecular electron transfer reactions of a few
tertiary amine appended dibenzobarrelenes and
bisdibenzobarrelenes
Description:
Department
of Applied Chemistry, Cochin University of Science and Technology
Premachandran,S K; Dr.Joy, George(Cochin University of Science And Technology, January , 1981)
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Abstract:
The thesis presents the results of the investigations on the crystallisation ‘behaviour, detect
structure end electrical properties of certain organic crystals---phthslic snhydride end potsssiun scid phthalate Hollow crystals of phthalic snhydride were grown from vapour. the norpholog of these hollow crystals were studied in detail and s. mechanism for their growth has been proposed. A closed crystal—vapour system was used to study the basal plane growth of the
whiskers and the sequential growth, observed, confirmed the mechanism suggested for hollow crystals. The dendritic crystals of phthslic enhydride were grown, both iron
the melt and solution. The observed morphologies of these dendrites ere described. Bpherulites of phthalic anhydride have been grown by the artificial initiation of nucleation, from melt and solution. The variation of the substructure oi’ these spherulites with the growth tenperature wee
investigated. The spherulitic filll having ribbon substructure were etched to reveal dislocations. A mechanism for the formation of the observed etch pattern has been suggested. the slip occurring in these ribbons were studied and the results are presented
Description:
Department of physics, Cochin University of Science And Technology
Vanaja, K A; Dr.Jayalekshmi, S(Cochin University of Science and Technology, May , 2011)
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Abstract:
In the present studies, various copper delafossite materials viz; CuAlO2,
CuGaO2, CuFeO2 , CuGa1-xFexO2, CuYO2 and CuCaxY1-xO2 were synthesised by
solid state reaction technique. These copper delafossite materials were grown in
thin film form by rf magnetron sputtering technique. In general copper
delafossites exhibit good optical transparency. The conductivity of the CuYO2
could be improved by Ca doping or by oxygen intercalation by annealing the film in oxygen atmosphere. It has so far been impossible to improve the p-type
conductivity of CuGaO2 significantly by doping Mg or Ca on the Ga site. The ptype
conductivity is presumed to be due to oxygen doping or Cu Vacancies [6].
Reports in literature show, oxygen intercalation or divalent ion doping on Ga
site is not possible for CuGaO2 thin films to improve the p-type conductivity.
Sintered powder and crystals of CuFeO2 have been reported as the materials
having the highest p-type conductivity [14, 15] among the copper and silver
delafossites. However the CuFeO2 films are found to be less transparent in the
visible region compared to CuGaO2. Hence in the present work, the solid
solution between the CuGaO2 and CuFeO2 was effected by solid state reaction,
varying the Fe content. The CuGa1-xFexO2 with Fe content, x=0.5 shows an
increase in conductivity by two orders, compared to CuGaO2 but the
transparency is only about 50% in the visible region which is less than that of
CuGaO2 The synthesis of α−AgGaO2 was carried out by two step process which
involves the synthesis of β-AgGaO2 by ion exchange reaction followed by the
hydrothermal conversion of the β-AgGaO2 into α-AgGaO2. The trace amount of
Ag has been reduced substantially in the two step synthesis compared to the
direct hydrothermal synthesis. Thin films of α-AgGaO2 were prepared on silicon
and Al2O3 substrates by pulsed laser deposition. These studies indicate the
possibility of using this material as p-type material in thin film form for
transparent electronics. The room temperature conductivity of α-AgGaO2 was
measured as 3.17 x 10-4 Scm-1and the optical band gap was estimated as 4.12 eV.
A transparent p-n junction thin film diode on glass substrate was fabricated
using p-type α-AgGaO2 and n-ZnO.AgCoO2 thin films with 50% transparency in the visible region were deposited
on single crystalline Al2O3 and amorphous silica substrates by RF magnetron
sputtering and p type conductivity of AgCoO2 was demonstrated by fabricating
transparent p-n junction diode with AgCoO2 as p-side and ZnO: Al as n-side
using sputtering. The junction thus obtained was found to be rectifying with a
forward to reverse current of about 10 at an applied voltage of 3 V.The present
study shows that silver delafossite thin films with p-type conductivity can be
used for the fabrication of active devices for transparent electronics applications.
Description:
Department of Physics,
Cochin University of Science and Technology
Nisha, M; Jayaraj, M K(Department of Physics, December , 2006)
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Abstract:
The increasing interest in the interaction of light with electricity and
electronically active materials made the materials and techniques for producing
semitransparent electrically conducting films particularly attractive. Transparent
conductors have found major applications in a number of electronic and
optoelectronic devices including resistors, transparent heating elements,
antistatic and electromagnetic shield coatings, transparent electrode for solar
cells, antireflection coatings, heat reflecting mirrors in glass windows and many
other. Tin doped indium oxide (indium tin oxide or ITO) is one of the most
commonly used transparent conducting oxides. At present and likely well into
the future this material offers best available performance in terms of
conductivity and transmittivity combined with excellent environmental stability,
reproducibility and good surface morphology.
Although partial transparency, with a reduction in conductivity, can be obtained
for very thin metallic films, high transparency and simultaneously high
conductivity cannot be attained in intrinsic stoichiometric materials. The only
way this can be achieved is by creating electron degeneracy in a wide bandgap
(Eg > 3eV or more for visible radiation) material by controllably introducing
non-stoichiometry and/or appropriate dopants. These conditions can be
conveniently met for ITO as well as a number of other materials like Zinc oxide,
Cadmium oxide etc.
ITO shows interesting and technologically important combination of properties
viz high luminous transmittance, high IR reflectance, good electrical
conductivity, excellent substrate adherence and chemical inertness. ITO is a key
part of solar cells, window coatings, energy efficient buildings, and flat panel
displays. In solar cells, ITO can be the transparent, conducting top layer that lets
light into the cell to shine the junction and lets electricity flow out. Improving
the ITO layer can help improve the solar cell efficiency. A transparent
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conducting oxide is a material with high transparency in a derived part of the
spectrum and high electrical conductivity. Beyond these key properties of
transparent conducting oxides (TCOs), ITO has a number of other key
characteristics. The structure of ITO can be amorphous, crystalline, or mixed,
depending on the deposition temperature and atmosphere. The electro-optical
properties are a function of the crystallinity of the material. In general, ITO
deposited at room temperature is amorphous, and ITO deposited at higher
temperatures is crystalline. Depositing at high temperatures is more expensive
than at room temperature, and this method may not be compatible with the
underlying devices.
The main objective of this thesis work is to optimise the growth conditions of
Indium tin oxide thin films at low processing temperatures. The films are
prepared by radio frequency magnetron sputtering under various deposition
conditions. The films are also deposited on to flexible substrates by employing
bias sputtering technique. The films thus grown were characterised using
different tools. A powder x-ray diffractometer was used to analyse the
crystalline nature of the films. The energy dispersive x-ray analysis (EDX) and
scanning electron microscopy (SEM) were used for evaluating the composition
and morphology of the films. Optical properties were investigated using the UVVIS-
NIR spectrophotometer by recording the transmission/absorption spectra.
The electrical properties were studied using vander Pauw four probe technique.
The plasma generated during the sputtering of the ITO target was analysed using
Langmuir probe and optical emission spectral studies.
Valsala Kumari, C K; Dr.Joy, George(Cochin University of Science and Technology, September 20, 1984)
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Abstract:
During the past few decades, a wide spread interest in the structural, optical, electrical and
other physical properties of the transition metal dichalcogenide layer compounds has evolved. The members of this family of compounds can be regarded as strongly bonded two dimensional chalcogen-metal~chalcogen layers which are loosely coupled to one another by the weak ven
der Waal's forces. Because of this type of bonding, the crystals are easily cleavable along the basal plane and show highly anisotropic properties. This thesis contains the growth and the study
of the physical properties of certain tin dichalcogenide crystals (SnS2 and SnSe2). Tin disulphide and tin diselenide crystallize in the hexagonal CdI2 type crystal structure. This structure consists of layers of tin atoms sandwiched between two layers of chalcogen atoms. A tin atom is surrounded by six chalcogen atoms octahedrally.In the layers the atoms are held together by
covalent bonding and in between the layers there is van der Waal's bonding.
Description:
Department of Physics, Cochin University of Science and Technology
Valsala Kumari, C K; Dr.Joy, George(Cochin University of Science and Technology, 1984)
[+]
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Abstract:
During the past few decades, a wide spread interest in the structural, optical, electrical and other physical properties of the transition metal dichalcogenide
layer compounds has evolved. The members of this family of compounds can be regarded as stronglybonded two dimensional chalcogen-metal-chalcogen layers
which are loosely coupled to one another by the weak van der Waal's forces. Because of this type of bonding, the crystals are easily cleavable along the basal plane and show highly anisotropic properties. This thesis contains the growth and the study of the physical properties of certain tin dichalcogenide
crystals (SnS2 and Snsea). Tin disulphide and tin diselenide crystallize in the hexagonal CdI2 type crystalstructure. This structure consists of layers of tin
atoms sandwiched between two layers of chalcogen atoms. Aitin atom is surrounded by six chalcogen atoms octahedrally. In the layers the atoms are held together by covalent bonding and in between the layers there is
van der Waal's bonding.
Description:
Department of Physics, Cochin University of Science and Technology
George, Peter; Dr.Joy, George(Cochin University Of Science And Technology, July 11, 1986)
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Abstract:
Over the past years there has been considerable interest in the
growth of single crystals both from the point of view of basic research
and technological application. With the revolutionary emergence
of solid state electronics which is based on single crystal technolo8Ys
basic and applied studies on crystal growth and characterization
_have gained a-more significant role in material science. These studies
are being carried out for single crystals not only of semiconductor
and other electronic materials but also of metals and insulators.
Many organic crystals belonging to the orthorhombic class exhibit
ferroelectric, electrooptic, triboluminescent and piezoelectric properties.
Diammonium Hydrogen Citrate (DAHC) crystals are reported to
be piezoelectric and triboluminescent /1/. Koptsik et al. /2/ have
reported the piezoelectric nature of Citric Acid Monohydrate (CA)
crystals. And since not much work has been done on these crystals,
it has been thought useful to grow and characterize these crystals.
This thesis presents a study of the growth of these crystals
from solution and their defect structures. The results of the microindentation and thermal analysis are presented. Dielectric, fractographic, infrared (IR) and ultraviolet (UV) studies of DAHC crystals are also reported
Description:
Department of Physics, Cochin University
of Science and Technology
Kunjomana, A G; Dr.Elizabeth, Mathai(Cochin University Of Science And Technology, August 10, 1992)
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Abstract:
The physical properties of solid matter are
basically influenced by the existence of lattice defects;
as a result the study of crystal defects has assumed
a central position in solid state physics and materials
science. The study of dislocations ixa single crystals
can yield a great deal of information on the mechanical
properties of materials. In order to secure a full understanding
of the processes taking place in semiconducting
materials, it is important to investigate the microhardness
of these materials-—the most reliable method of
determining the fine structure of crystals, the revelation
of micro—inhomogenities in the distribution of impurities,
the effect of dislocation density on the mechanical
properties of crystals etc. Basically electrical conductivity
in single crystals is a defect controlled phenomenon
and hence detailed investigation of the electrical properties
of these materials is one of the best available
methods for the study of defects in them. In the present
thesis a series of detailed studies carried out in Te—Se
system, Bi2Te3 and In2Te3 crystals using surface topographical,
dislocation and microindentation analysis as well as
electrical measurements are presented
Description:
Department of
Physics, Cochin University of Science and Technology
Ajimsha, R S; Jayaraj, M K(Department of Physics, February , 2008)
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Abstract:
Transparent conducting oxides (TCO’s) have been known and used for technologically important applications for more than 50 years. The oxide materials such as In2O3, SnO2 and impurity doped SnO2: Sb, SnO2: F and In2O3: Sn (indium tin oxide) were primarily used as TCO’s. Indium based oxides had been widely used as TCO’s for the past few decades. But the current increase in the cost of indium and scarcity of this material created the difficulty in obtaining low cost TCO’s. Hence the search for alternative TCO material has been a topic of active research for the last few decades. This resulted in the development of various binary and ternary compounds. But the advantages of using binary oxides are the easiness to control the composition and deposition parameters. ZnO has been identified as the one of the promising candidate for transparent electronic applications owing to its exciting optoelectronic properties. Some optoelectronics applications of ZnO overlap with that of GaN, another wide band gap semiconductor which is widely used for the production of green, blue-violet and white light emitting devices. However ZnO has some advantages over GaN among which are the availability of fairly high quality ZnO bulk single crystals and large excitonic binding energy. ZnO also has much simpler crystal-growth technology, resulting in a potentially lower cost for ZnO based devices.
Most of the TCO’s are n-type semiconductors and are utilized as transparent electrodes in variety of commercial applications such as photovoltaics, electrochromic windows, flat panel displays. TCO’s provide a great potential for realizing diverse range of active functions, novel functions can be integrated into the materials according to the requirement. However the application of TCO’s has been restricted to transparent electrodes,
ii
notwithstanding the fact that TCO’s are n-type semiconductors. The basic reason is the lack of p-type TCO, many of the active functions in semiconductor originate from the nature of pn-junction. In 1997, H. Kawazoe et al reported the CuAlO2 as the first p-type TCO along with the chemical design concept for the exploration of other p-type TCO’s. This has led to the fabrication of all transparent diode and transistors.
Fabrication of nanostructures of TCO has been a focus of an ever-increasing number of researchers world wide, mainly due to their unique optical and electronic properties which makes them ideal for a wide spectrum of applications ranging from flexible displays, quantum well lasers to in vivo biological imaging and therapeutic agents. ZnO is a highly multifunctional material system with highly promising application potential for UV light emitting diodes, diode lasers, sensors, etc. ZnO nanocrystals and nanorods doped with transition metal impurities have also attracted great interest, recently, for their spin-electronic applications
This thesis summarizes the results on the growth and characterization of ZnO based diodes and nanostructures by pulsed laser ablation. Various ZnO based heterojunction diodes have been fabricated using pulsed laser deposition (PLD) and their electrical characteristics were interpreted using existing models. Pulsed laser ablation has been employed to fabricate ZnO quantum dots, ZnO nanorods and ZnMgO/ZnO multiple quantum well structures with the aim of studying the luminescent properties.
Sreeja, R; Dr.Jayaraj, M K(Cochin University Of Science And Technology, July 6, 2011)
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Abstract:
Nonlinear optics has been a rapidly growing field in recent decades since the
invention of lasers. The systematic progress in the laser technology increases our
efficiency in the generation and control of coherent optical radiations. Nonlinear
optics is based on the study ofeffects and phenomena related to the interaction of
intense coherent light radiation with matter. Compared to other light sources laser radiation can provide high directionality, high monochromaticiry, high brightness
and high photon degeneracy. At such a very intense incident beam, the matter
responds in a nonlinear manner to the incident radiation fields, which endows the
media :1 characteristic to change the refractive index or absorption coe fflcient of the
media or the wavelength, or the frequency of the incident electromagnetic waves.
This thesis encompasses the fabrication of nonlinear optical devices based on
semiconductor and metal nanostructures. The presented work focus on the
experimental and theoretical discussions on nonlinear optical effects especially
nonlinear absorption and refraction exhibitted by metal and semiconductor nanostructures
Description:
Optoelectronic Devices Laboratory
Department of Physics
Cochin University of Science and Technology
Joy, C M; Dr.Balakrishnan, K P(Cochin University of Science and Technology, April , 1989)
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Abstract:
The thesis entitled Growth Response of Phytoplankton Exposed to Industrial Effluents in River Periyar. The present investigation has been conducted in two phases: field observation and algal assays. The monthly distribution of hydrographic features is represented graphically. The sampling year has been divided into three seasons: monsoon (June to September), postmonsoon (October to January) and premonsoon (February to May). The data were analysed using Student's t-test to find whether there was any significant difference between surface and bottom samples. The spatial variation of the variables was assessed by Page's L (trend) test (Ray Meddis, 1975). The standard procedure for algal toxicity test (Ward and Parrish, 1982) was followed throughout the study. Statistical analysis (Page's L (trend) test) showed that there was no significant difference in Secchi disc transparency between the stations. The field observations as well as the laboratory assays confirm that the rate of discharge in river Periyar during premonsoon is insufficient to effect dilution of wastewater received in the industrial zone.
Description:
School of Environmental Studies,
Cochin University of Science
and Technology.
Bindu Bhaskaran, A B; Dr.Mohammed Salih,K Y(Cochin University Of Science And Technology, March 14, 2011)
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Abstract:
Fishes are one of the most important members of the aquatic food chain, and
through them some toxicants may reach human beings as well. The selection of
organisms for toxicity test is mainly based on certain criteria like its ecological
status, position within the food chain, suitability for laboratory studies, genetically
stable, uniform populations and adequate background data on the organism
(Buikema et al., 1982). The species selected for the present study Etroplus
maculatus satisfy most of the above protocols. Rechten (1980) opined it as a
laboratory favorite of fish researchers. However, there are difficulties in the rise of
fishes for pollution assessment impact. Most important of these is our limited
understanding of the mechanism of toxicity. The interpretation of the significance or specificity of a measured biological response could there for become difficult.
Not withstanding these limitations, attempts have been made to the normal
haematology and to analyze the impact of heavy metal at realistic levels to the
experimental media, on the haematology, and enzymatic activity and histology of
Etroplus maculatus
Description:
Dept. of Marine Biology, Microbiology and Biochemistry
Cochin University of Science and Technology
Annies, Joseph; Dr.Rosamma,Philip(Cochin University of Science and Technology, July , 2008)
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Abstract:
This thesis Entitled Haematological responses of penaeus monodon to environmental alterations and pathogenic invasion. Thesis concluded from the present study that stress is accompanied by
alterations in haemolymph metabolic variables and immune responses that influences the susceptibility of P. monodon to infection. Acute salinity variations were proved to be a stress condition that enhances the susceptibility of P. monodon to V. harveyi and WSSV infection. Ambient Cu at 0.1 mg 1" and ambient Zn at 1.0 mg 1" proved immunostimulatory in increasing the immunocompetence of P. monodon to WSSV infection and higher concentrations of Cu and Zn proved immunosuppressive.
Haemolymph total protein, total carbohydrates and total lipids showed the highest relation with immune responses. THC, PO, ACP and ALP that greatly correlated with the survival rate proposed as reliable biomarkers of health in P. monodon. The study highlights the need for proper management practices and regular health monitoring to be adopted to avoid mass mortality in shrimp culture ponds.
Description:
Department of Marine Biology, Microbiology and Biochemistry,
School of Ocean Science and T echnology,
Cochin University of Science and Technology
Selven,S; Dr.Rosamma,Philip(Cochin University of Science and Technology, May , 2008)
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Abstract:
Aquaculture has developed to become one of the fastest growing food producing sectors in the world.Today India is one among the major shrimp producing countries in the world.There are extensive and intensive shrimp culture practices. In
extensive shrimp culture, shrimps are stocked at low densities (< 25 PLs m'2)in large ponds or tidal enclosures in which little or no management is exercised or possible. Farmers depend almost entirely on natural conditions in extensive cultures. Intensive shrimp culture is carried out in
high densities (>200 PLs m'2). Much of the world shrimp production still comes from extensive culture.There is a growing demand for fish and marine products for human and animal consumption. This demand has led to rapid growth of
aquaculture, which some times has been accompanied by ecological impacts and economic loss due to diseases. The expansion of shrimp culture always accompanies local environmental degradation and
occurrence of diseases.Disease out breaks is recognised as a significant constraint to aquaculture production. Environmental factors, water quality, pollution due to effluent discharge and pathogenic invasion due to vertical
and horizontal transmission are the main causes of shrimp disease out breaks. Nutritional imbalance, toxicant and other pollutants also account for the onset of diseases.
pathogens include viruses, bacteria, fungi and parasites.Viruses are the most economically significant pathogens of the cultured shrimps world wide. Disease control in shrimp aquaculture should focus first on preventive measures for eliminating disease promoting factors.ln order to design prophylactic and proactive measures against shrimp diseases, it is mandatory to understand the immune make up of the cultivable species,
its optimum culture conditions and the physico chemical parameters of the rearing environment. It has been proven beyond doubt that disease is an end result of complex interaction of environment, pathogen and the host animal. The aquatic environment is abounded with infectious microbes.The transmission of disease in this environment is extremely easy,
especially under dense, culture conditions. Therefore, a better understanding of the immune responses of the cultured animal in relation to its environmental alterations and microbial invasions is essential indevising strategic measures against aquaculture loss due to diseases. This study accentuate the importance of
proper and regular health monitoring in shrimps employing the most appropriate haematological biomarkers for application of suitable prophylactic measures in order to avoid serious health hazards in shrimp culture systems.
Suresh, K; Dr.Mohandas, A(Cochin University of Science And Technology, January , 1988)
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Abstract:
It is well known that under certain conditions, populations of oysters
and clams are susceptible to destructive epizootics caused by pathogenic
micro-organisms. It has also been shown that exposure of mammals to certain
heavy metals causes increased susceptibility to and severity of microbial
infections (Koller, 1980). Consequently, pollutants that affect haemocyte
viability or interfere with internal defence functions of the haemocytes which
are considered as the major means of defence in moliuscs against invading
foreign organisms and pathogens (Cheng, 1981) may have profound effect on
long term survival of molluscan populations. All these justify the significance
of the present study in the context of the current status on molluscan
culture programme, and how the data on molluscan haematological studies
.could be taken as the reliable criteria for pollution monitoring studies.
Description:
School of Marine Sciences, Cochin University of Science and Technology
Neil, Scholastin Correya; Dr.Rosamma,Philip(Cochin University of Science And Technology, October , 2012)
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Abstract:
The marine environment is indubitably the largest contiguous habitat on
Earth. Because of its vast volume and area, the influence of the world ocean on
global climate is profound and plays an important role in human welfare and
destiny. The marine environment encompasses several habitats, from the sea
surface layer down through the bulk water column, which extends >10,000 meters
depth, and further down to the habitats on and under the sea floor. Compared to
surface habitats, which have relatively high kinetic energy, deep-ocean circulation
is very sluggish. By comparison, life in the deep sea is characterized by a relatively
constant physical and chemical environment. Deep water occupying the world
ocean basin is a potential natural resource based on its properties such as low
temperature, high pressure and relatively unexplored properties. So, a judicious
assessment of the marine resources and its management are essential to ensure
sustainable development of the country’s ocean resources.
Marine sediments are complex environments that are affected by both
physiological and biological factors, water movements and burrowing animals.
They encompass a large extent of aggregates falling from the surface waters. In
aquatic ecosystems, the flux of organic matter to the bottom sediments depend on
primary productivity at the ocean surface and water depth. Over 50% of the earth’s
surface is covered by deep-sea sediments that are primarily formed through the
continual deposition of particles from the productive pelagic waters (Vetriani et al.,
1999). These aggregates are regarded as ‘hot spots’ of microbial activity in the
ocean (Simon et al., 2002). This represents a good nutritional substrate for
heterotrophic bacteria and favours bacterial growth
Description:
School of Marine Sciences, Cochin University of Science And Technology
Santhi, Thirumani S; Dr.Chandrika, V(Cochin University of Science And Technology, June , 1992)
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Abstract:
The principal interest of the present investigation was to determine
seasonal and vertical variation of chemoorganotrophic utilisation of glucose
and sodium—acetate by the natural bacterial population in the aquaculture
pond of Narakkal, Cochin using techniques which allow maintenance of
the in situ gaseous concentrations during incubation. In addition salinity,
dissolved oxygen, temperature, hydrogen—ion—.concentration, primary production,
plant pigments and total bacterial concentration were determined
seasonally and vertically because of their possible relationship to chemoorganotrophy.
Hamsakutty, V; Dr.Mathew, K T(Cochin University of Science and Technology, March , 2007)
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Abstract:
In this thesis, the author proposes a new geometry DR antenna-the Hexagonal Dielectric Resonator Antenna(HDRA)-capable of multiple frequency operation on a single feed of excitation.This avoids the conventional use of miniaturizes the structure.The properties of the HDRA on microstrip as well as coaxial feeding have been studied.The analysis of radiation characteristics indicates a gain comparable with other shapes.The antenna is capable of providing efficiency around 98%.The simulation using HFSS also yields results in conformity with the experimental results.Mode analysis is carried out and the modes are identified.The determination of the reflection characteristics through theoretical analysis using FDTD validates the multifrequency operation of the antenna,The antenna finds application in DCT,PCS and WLAN bands.
Description:
Department of
Electronics, Cochin University of Science and Technology
Vimalkumar, T V; Dr.Vijayakumar, K P(Cochin University of Science & Technology, August , 2011)
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Abstract:
In the present work we report the preparation details studies on ZnO thin films. ZnO
thin films are prepared using cost effective deposition technique viz., Chemical Spray
Pyrolysis (CSP). The method is very effective for large area preparation of the ZnO thin
film. A new post-deposition process could also be developed to avoid the adsorption of
oxygen that usually occurs after the spraying process i.e., while cooling. Studies were done
by changing the various deposition parameters for optimizing the properties of ZnO thin
film. Moreover, different methods of doping using various elements are also tried to
enhance the conductivity and transparency of the film to make these suitable for various
optoelectronic applications.
Description:
Department of Physics,
Cochin University of Science and Technology