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