A Study of the Physical and Engineering Behaviour of Cochin Marine Clays

With the increase in population, housing and construction of various facilities have been a problem with urbanization. Having exhausted all the trouble free hand, man is nowon the lookout for techniques to improve areas which were originally considered uninhabitable. Thus this study is based on the nature and engineering behavior of soft clays covering long stretches of coastal line and methods to improve their geotechnical properties .The main aim of the present investigation is to study in detail the physical and engineering behavior of the marine clays of Cochin. While it is well known that the marine clays have been posing numerous problems to foundation engineers all along, the relevant literature reveals that no systematic and comprehensive study has been attempted to date. The: knowledge gained through the study is suitably used to improve these properties with appropriate additives.

Studies on the propagation of errors in physical oceanographic computations

The results of an investigation on the limits of the random errors contained in the basic data of Physical Oceanography and their propagation through the computational procedures are presented in this thesis. It also suggest a method which increases the reliability of the derived results. The thesis is presented in eight chapters including the introductory chapter. Chapter 2 discusses the general theory of errors that are relevant in the context of the propagation of errors in Physical Oceanographic computations. The error components contained in the independent oceanographic variables namely, temperature, salinity and depth are deliniated and quantified in chapter 3. Chapter 4 discusses and derives the magnitude of errors in the computation of the dependent oceanographic variables, density in situ, gt, specific volume and specific volume anomaly, due to the propagation of errors contained in the independent oceanographic variables. The errors propagated into the computed values of the derived quantities namely, dynamic depth and relative currents, have been estimated and presented chapter 5. Chapter 6 reviews the existing methods for the identification of level of no motion and suggests a method for the identification of a reliable zero reference level. Chapter 7 discusses the available methods for the extension of the zero reference level into shallow regions of the oceans and suggests a new method which is more reliable. A procedure of graphical smoothening of dynamic topographies between the error limits to provide more reliable results is also suggested in this chapter. Chapter 8 deals with the computation of the geostrophic current from these smoothened values of dynamic heights, with reference to the selected zero reference level. The summary and conclusion are also presented in this chapter.

Development of optical fiber sensors for selected chemical and physical sensing applications

The objective of the preset work is to develop optical fiber sensors for various physical and chemical parameters. As a part of this we initially investigated trace analysis of silica, ammonia, iron and phosphate in water. For this purpose the author has implemented a dual wavelength probing scheme which has many advantages over conventional evanescent wave sensors. Dual wavelength probing makes the design more reliable and repeatable and this design makes the sensor employable for concentration, chemical content, adulteration level, monitoring and control in industries or any such needy environments. Use of low cost components makes the system cost effective and simple. The Dual wavelength probing scheme is employed for the trace analysis of silica, iron, phosphate, and ammonia in water. Such sensors can be employed for the steam and water quality analysers in power plants. Few samples from a power plant are collected and checked the performance of developed system for practical applications.

Physical characteristics of the coastal waters off the south-west coast of india with an attempt to study the possible relationship with sardine mackerel and anchovy fisheries

The present study is aimed at observing the variations, in space and time, of see of the important hydrographic parameters such as sea water temperature, salinity and Resolved oxygen within the coastal waters along the south-west coast of Indiametween Ratnagiri (17°OO*N,73°20'E) and cape comorin ( 8°10'N,77°30*E). Specific data relating to the process of upwelling and sinking was collected mainly to evaluate the extent and intensity of the vertical mixing processes active in the area under study. The study also attempted possible correlations between the observed parameters and the occurrence and migrations of some of the major pelagic fishery resources such as sardine,mackerel and anchovy in the area under study

Materials for Fish Nets-Their Properties, Selection and Preservation

The properties of synthetic fibres vary with thc inherent physical characteristics of the basic raw materials used mode of preparation of yarns and method of construction of twines. Since the synthetic fibres as maufactured from polymers which are synthesized from simple chemical units, the qualities of man-made fibres can he influenced by the process of manufacture and certain modifications can even be introduced at the processing stage to meet any specific requirement to a certain extent. Hence, an elaborate study of the properties of fish not twines produced has been taken up with a view to determining their suitability for various types of fishing gear with particular reference to conditions prevailing in India.

Study of Synchronisalion and Control of Chaos in Directly Modulated Semiconductor Lasers

Chaos is a subject oftopical interest and, studied in great detail in relation to its relevance in almost all branches of science, which include physical, chemical, and biological fields. Chaos in the literal sense signifies utter confusion, but the scientific community has differentiated chaos as deterministic chaos and white noise. Deterministic chaos implies the complex behaviour of systems, which are governed by deterministic laws. Behaviour of such systems often become unpredictable in the long run. This unpredictability arises from the sensitivity of the system to its initial conditions. The essential requirement for ‘sensitivity to initial condition’ is nonlinearity of the system. The only method for determining the future of such systems is numerically simulating its final state from a set ofinitial conditions. Synchronisation

Source Characterization of Sedimentary Organic Matter in a Tropical Estuary, Southwest Coast of India: A Biomarker Approach

The source, fate and diagentic pathway of sedimentary organic matter in estuaries are difficult to delineate due to the complexity of organic matter sources, intensive physical mixing and biological processes. A combination of bulk organic matter techniques and molecular biomarkers are found to be successful in explaining organic matter dynamics in estuaries. The basic requirement for these multi-proxy approaches are (i) sources have significantly differing characteristics, (ii) there are a sufficient number of tracers to delineate all sources and (iii) organic matter degradation and processing have little, similar or predictable effects on end member characteristics. Although there have been abundant researches that have attempted to tackle difficulties related to the source and fate of organic matter in estuarine systems, our understanding remains limited or rather inconsistent regarding the Indian estuaries. Cochin estuary is the largest among many extensive estuarine systems along the southwest coast of India. It supports as much biological productivity and diversity as tropical rain forests. In this study, we have used a combination of bulk geochemical parameters and different group of molecular biomarkers to define organic matter sources and thereby identifying various biogeochemical processes acting along the salinity gradient of the Cochin estuary