Studies on some generalizations of line graph and the power domination problem in graphs

Department of Mathematics, Cochin University of Science and Technology

Ecological characteristics of prawn culture fields in the Cochin area

Prawn culture by traditional method forms an important occupation for the people in these areas, especially in the Vypeen island. Though short term studies have been made on various aspects of prawn culture field and its ecology, a study of detailed nature covering perennial, seasonal, fields and canals between coconut plantation is lacking from these areas. This study will also enable to assess the relative productivity of different systems during different seasons and the influence of the environment on the production potentials. Therefore the present study is taken upto throw more light on the ecological characteristics of these fields with special emphasis on its primary, secondary and tertiary production. The present area of investigation includes the prawn culture fields adjacent to Cochin backwater. The Cochin backwater (O9° 58'N 76° 28'E) is a shallow semi-enclosed body of water of tropical estuary. A narrow gut, about 450 M wide forms its main connection with the Arabian sea and this region is subjected to regular tidal influenceertiary production.

Occurrence of filamentous algae and soil characteristics in the paddy fields of Kuttanad and Kole lands of Kerala

The present work is the study of filamentous algae in the paddy fields of Kuttanad and Kole lands of Kerala. This investigation was initiated by sampling of filamentous algae in Kuttanad during December 2010 to February 2011. A second phase of sampling was done from November 2011 to February 2012. The sampling periodicity corresponded to the crop growth starting from field preparation through sowing, and continued till the harvest. Sampling locations were selected from the active paddy cultivation regions of the six agronomic zones of Kuttanad. The numbers of sampling locations were proportional to the area of each zone. Algae of the Kole lands were collected during from October 2011 to January 2012. It was observed that blue-green algae dominated in both Kuttanad and Kole lands. Thirty two species of blue-green algae and eight species of green algae were identified from Kuttanad. The highest number of algal species was observed from Kayal lands in Kuttanad throughout the cropping season. Among the thirty two species of blue-green algae twenty five species are nonheterocystous and seven species are heterocystous. Twenty eight species of blue-green and six species of green algae were identified from Kole lands, and highest number of species was observed in Palakkal throughout the cropping season. Among the twenty eight species of blue-green algae collected from Kole lands twenty one species are non-heterocystous, and only seven species are heterocystous filamentous algae. Blooms of Spirogyra were observed during the second phase of sampling in Kuttanad and also in the Kole lands. The results of the germination study revealed that the extract of Spirogyra sp. inhibited seed germination and reduced seedling vigour. The growth of the treated seedlings was evaluated by pot experiments. The results clearly showed that Spirogyra sp. can negatively affect the seed germination, seedling vigour, and the yield of rice.

AN INVESTIGATION ON AIR-SEA INTERACTION IN THE INDIAN OCEAN DURING CONTRASTING MONSOONS

The study is undertaken with an objective to investigate the linkage between air-sea fluxes in the Indian Ocean and monsoon forcing. Since the monsoon activity is linked to fluxes, the variability of surface marine meteorological fields under the variable monsoon conditions is also studied. The very objective of the present study is to document various sea surface parameters of the Indian Ocean and to examine the anomalies found in them. Hence it is attempted to relate the anomaly to the variability of monsoon over India, highlighting the occasion of contrasting monsoon periods. The analysis of anomalies of surface meteorological fields such as SST, wind speed and direction, sea level pressure and cloud cover for contrasting monsoons are also studied. During good monsoon years, the pressure anomalies are negative indicating a fall in SLP during pre-monsoon and monsoon months. The interaction of the marine atmosphere with tropical Indian Ocean and its influence on ISMR continue to be an area of active research.

Dielectric Behavior of Natural Rubber Composites in Microwave Fields

In this article, we report the preparation of conducting natural rubber (NR) with polyaniline (Pani). NR was made into a conductive material by the compounding of NR with Pani in powder form. NR latex was made into a conductive material by the in situ polymerization of aniline in the presence of NR latex. Different compositions of Pani- NR semi-interpenetrating networks were prepared, and the dielectric properties of all of the samples were determined in microwave frequencies. The cavity perturbation techpique was used for this study. A HP8510 vector network analyzer with a rectangular cavity resonator was used for this study. S bands 2-4 GHz in frequency were used. Thermal studies were also carried out with thermogravimetric analysis and differential scanning calorimetry.

Dielectric Behavior of Natural Rubber Composites in Microwave Fields

In this article, we report the preparation of conducting natural rubber (NR) with polyaniline (Pani). NR was made into a conductive material by the compounding of NR with Pani in powder form. NR latex was made into a conductive material by the in situ polymerization of aniline in the presence of NR latex. Different compositions of Pani- NR semi-interpenetrating networks were prepared, and the dielectric properties of all of the samples were determined in microwave frequencies. The cavity perturbation techpique was used for this study. A HP8510 vector network analyzer with a rectangular cavity resonator was used for this study. S bands 2-4 GHz in frequency were used. Thermal studies were also carried out with thermogravimetric analysis and differential scanning calorimetry.

Re-engineering and Re-defining University Libraries in the context of modern Information and Communication Technologies: a study with special reference to the University Libraries in Kerala

Information and communication technologies are the tools that underpin the emerging “Knowledge Society”. Exchange of information or knowledge between people and through networks of people has always taken place. But the ICT has radically changed the magnitude of this exchange, and thus factors such as timeliness of information and information dissemination patterns have become more important than ever.Since information and knowledge are so vital for the all round human development, libraries and institutions that manage these resources are indeed invaluable. So, the Library and Information Centres have a key role in the acquisition, processing, preservation and dissemination of information and knowledge. ln the modern context, library is providing service based on different types of documents such as manuscripts, printed, digital, etc. At the same time, acquisition, access, process, service etc. of these resources have become complicated now than ever before. The lCT made instrumental to extend libraries beyond the physical walls of a building and providing assistance in navigating and analyzing tremendous amounts of knowledge with a variety of digital tools. Thus, modern libraries are increasingly being re-defined as places to get unrestricted access to information in many formats and from many sources.The research was conducted in the university libraries in Kerala State, India. lt was identified that even though the information resources are flooding world over and several technologies have emerged to manage the situation for providing effective services to its clientele, most of the university libraries in Kerala were unable to exploit these technologies at maximum level. Though the libraries have automated many of their functions, wide gap prevails between the possible services and provided services. There are many good examples world over in the application of lCTs in libraries for the maximization of services and many such libraries have adopted the principles of reengineering and re-defining as a management strategy. Hence this study was targeted to look into how effectively adopted the modern lCTs in our libraries for maximizing the efficiency of operations and services and whether the principles of re-engineering and- redefining can be applied towards this.Data‘ was collected from library users, viz; student as well as faculty users; library ,professionals and university librarians, using structured questionnaires. This has been .supplemented by-observation of working of the libraries, discussions and interviews with the different types of users and staff, review of literature, etc. Personal observation of the organization set up, management practices, functions, facilities, resources, utilization of information resources and facilities by the users, etc. of the university libraries in Kerala have been made. Statistical techniques like percentage, mean, weighted mean, standard deviation, correlation, trend analysis, etc. have been used to analyse data.All the libraries could exploit only a very few possibilities of modern lCTs and hence they could not achieve effective Universal Bibliographic Control and desired efficiency and effectiveness in services. Because of this, the users as well as professionals are dissatisfied. Functional effectiveness in acquisition, access and process of information resources in various formats, development and maintenance of OPAC and WebOPAC, digital document delivery to remote users, Web based clearing of library counter services and resources, development of full-text databases, digital libraries and institutional repositories, consortia based operations for e-journals and databases, user education and information literacy, professional development with stress on lCTs, network administration and website maintenance, marketing of information, etc. are major areas need special attention to improve the situation. Finance, knowledge level on ICTs among library staff, professional dynamism and leadership, vision and support of the administrators and policy makers, prevailing educational set up and social environment in the state, etc. are some of the major hurdles in reaping the maximum possibilities of lCTs by the university libraries in Kerala. The principles of Business Process Re-engineering are found suitable to effectively apply to re-structure and redefine the operations and service system of the libraries. Most of the conventional departments or divisions prevailing in the university libraries were functioning as watertight compartments and their existing management system was more rigid to adopt the principles of change management. Hence, a thorough re-structuring of the divisions was indicated. Consortia based activities and pooling and sharing of information resources was advocated to meet the varied needs of the users in the main campuses and off campuses of the universities, affiliated colleges and remote stations. A uniform staff policy similar to that prevailing in CSIR, DRDO, ISRO, etc. has been proposed by the study not only in the university libraries in kerala but for the entire country.Restructuring of Lis education,integrated and Planned development of school,college,research and public library systems,etc.were also justified for reaping maximum benefits of the modern ICTs.

Bayesian Inference in Exponential and Pareto populations in the presence of Outliers

This thesis Entitled Bayesian inference in Exponential and pareto populations in the presence of outliers. The main theme of the present thesis is focussed on various estimation problems using the Bayesian appraoch, falling under the general category of accommodation procedures for analysing Pareto data containing outlier. In Chapter II. the problem of estimation of parameters in the classical Pareto distribution specified by the density function. In Chapter IV. we discuss the estimation of (1.19) when the sample contain a known number of outliers under three different data generating mechanisms, viz. the exchangeable model. Chapter V the prediction of a future observation based on a random sample that contains one contaminant. Chapter VI is devoted to the study of estimation problems concerning the exponential parameters under a k-outlier model.

Studies on Thermal structure in the seas around in India

The thesis entitled Studies on Thermal Structure in the Seas Around India. An attempt is made in this study to document the observed variability of thermal structure, both on seasonal and short-term scales, in the eastern Arabian Sea and southwestern Bay of Bengal, from the spatial and time series data sets from a reasonably strong data base. The present study has certain limitations. The mean temperatures are based on an uneven distribution of data in space and time. Some of the areas, although having a ‘full annual coverage, do not have adequate data for some months. Some portions in the area under study are having data gaps. The consistency and the coherence in the internal wave characteristics could not be examined due to non-availability of adequate data sets. The influence of generating mechanisms; other than winds and tides on the observed internal wave fields could not be ascertained due to lack of data. However, a comprehensive and intensive data collection can overcome these limitations. The deployment of moored buoys with arrays of sensors at different depths at some important locations for about 5 to 10 years can provide intensive and extensive data sets. This strong data base can afford to address the short-term and seasonal variability of thermal field and understand in detail the individual and collective influences of various physical and dynamical mechanisms responsible for such variability.

Studies on upwelling and sinking in the seas around india

Of the several physical processes occurring in the sea, vertical motions have special significance because of their marked effects on the oceanic environment. upwelling is the process in the sea whereby subsurface layers move up towards the surface. The reverse process of surface water sinking to subsurface depths is called sinking. Upwelling is a very conspicuous feature along the west coasts of continents and equatorial regions, though upwelling also occurs along certain east coasts of continents and other regions, The Thesis is an outcome of some investigations carried out by the author on upwelling and sinking off the west and east coasts of India. The aim of the study is to find out the actual period and duration of upwelling and sinking, their driving mechanism, various associated features and the factors that affect these processes. It is achieved by analysing the temperature and density fields off the west and east coasts of India, and further conclusions are drawn from the divergence field of surface currents, wind stress and sea level variations.

Analysis of Fluctuations in the Early Universe Using Fokker-Planck Formalism

The thesis begins with a review of basic elements of general theory of relativity (GTR) which forms the basis for the theoretical interpretation of the observations in cosmology. The first chapter also discusses the standard model in cosmology, namely the Friedmann model, its predictions and problems. We have also made a brief discussion on fractals and inflation of the early universe in the first chapter. In the second chapter we discuss the formulation of a new approach to cosmology namely a stochastic approach. In this model, the dynam ics of the early universe is described by a set of non-deterministic, Langevin type equations and we derive the solutions using the Fokker—Planck formalism. Here we demonstrate how the problems with the standard model, can be eliminated by introducing the idea of stochastic fluctuations in the early universe. Many recent observations indicate that the present universe may be approximated by a many component fluid and we assume that only the total energy density is conserved. This, in turn, leads to energy transfer between different components of the cosmic fluid and fluctuations in such energy transfer can certainly induce fluctuations in the mean to factor in the equation of state p = wp, resulting in a fluctuating expansion rate for the universe. The third chapter discusses the stochastic evolution of the cosmological parameters in the early universe, using the new approach. The penultimate chapter is about the refinements to be made in the present model, by means of a new deterministic model The concluding chapter presents a discussion on other problems with the conventional cosmology, like fractal correlation of galactic distribution. The author attempts an explanation for this problem using the stochastic approach.

Ecotoxic Metal Records and its Degree of Geochemical Symphony in the Niche of Cochin Estuarine System- A Theraptic Perspective

The heavy metal contamination in the environment may lead to circumstances like bioaccumulation and inturn biomagnification. Hence cheaper and effective technologies are needed to protect the precious natural resources and biological lives. A suitable technique is the one which meets the technical and environmental criteria for dealing with a particular remediation problem and should be site-specific due to spatial and climatic variations and it may not economically feasible everywhere. The search for newer technologies for the environmental therapy, involving the removal of toxic metals from wastewaters has directed attention to adsorption, based on metal binding capacities of various adsorbent materials. Therefore, the present study aim to identify and evaluate the most current mathematical formulations describing sorption processes. Although vast amount of research has been carried out in the area of metal removal by adsorption process using activated carbon few specific research data are available in different scientific institutions. The present work highlights the seasonal and spatial variations in the distribution of some selected heavy metals among various geochemical phases of Cochin Estuarine system and also looked into an environmental theraptic/remedial approach by adsorption technique using activated charcoal and chitosan, to reduce and thereby controlling metallic pollution. The thesis has been addressed in seven chapters with further subdivisions. The first chapter is introductory, stating the necessity of reducing or preventing water pollution due to the hazardous impact on environment and health of living organisms and drawing it from a careful review of literature relevant to the present study. It provides a constricted description about the study area, geology, and general hydrology and also bears the major objectives and scope of the present study.

Thermohaline variability in the upper layers of the Arabian Sea

The Arabian Sea is an area of complex air-sea interaction processes with seasonal reversing monsoons. The associated thermohaline variability in the upper layers appears to control the large scale monsoon flow which is not yet completely understood. The variability in the thermohaline fields is known to occur in temporal domain ranging from intra-diurnal to inter-annual time scales and on spatial domains of few tens of kilometers to few thousands of kilometers. In the Arabian Sea though the surface temperature was routinely measured by both conventional measurements and satellites, the corresponding information on the subsurface thermohaline field is very sparse due to the lack cw adequate measurements. In such cases the numerical models offer promise in providing information on the subsurface features given an initial thermohaline field and surface heat flux boundary conditions. This thesis is an outcome of investigations carried out on the various aspects of the thermohaline variability on different time scales. In addition to the description of the mean annual cycle. the one dimensional numerical models of Miller (1976) and Price et a1 (1986) are utilised to simulate the observed mixed layer characteristics at selected locations in the Arabian Sea on time scales ranging from intra-diurnal to synoptic scales under variable atmospheric forcing.