Effects and Modifications in In/Se and In/Sb Systems by Swift Heavy Ion Irradiation

Department of Physics, Cochin University of Science and Technology

Sulphur Chemistry in Mangrove Systems of Tropical Cochin Estuary

Sulphur is a non conservative major element and is the most active species in the redox processes in nature, especially in aquatic environment . The varying oxidative states from-2 to +6 make it possible to enter into many of the biogeochemical processes. Thus the history, present and future of the chemical composition and behaviour of the natural aquatic systems and sediments have footprints of the sulphur chemistry.Mangroves are considered to be the most productive, fishery supportive ecosystem operating in the intertidal regions. The interlinking of the mangroves with the sulphur chemistry is attempted here.

Information Discovery in Distributed Systems-A Novel Concept Based on Modelling of Information Elements

Sharing of information with those in need of it has always been an idealistic goal of networked environments. With the proliferation of computer networks, information is so widely distributed among systems, that it is imperative to have well-organized schemes for retrieval and also discovery. This thesis attempts to investigate the problems associated with such schemes and suggests a software architecture, which is aimed towards achieving a meaningful discovery. Usage of information elements as a modelling base for efficient information discovery in distributed systems is demonstrated with the aid of a novel conceptual entity called infotron.The investigations are focused on distributed systems and their associated problems. The study was directed towards identifying suitable software architecture and incorporating the same in an environment where information growth is phenomenal and a proper mechanism for carrying out information discovery becomes feasible. An empirical study undertaken with the aid of an election database of constituencies distributed geographically, provided the insights required. This is manifested in the Election Counting and Reporting Software (ECRS) System. ECRS system is a software system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous statutory reports.Most of the distributed systems of the nature of ECRS normally will possess a "fragile architecture" which would make them amenable to collapse, with the occurrence of minor faults. This is resolved with the help of the penta-tier architecture proposed, that contained five different technologies at different tiers of the architecture.The results of experiment conducted and its analysis show that such an architecture would help to maintain different components of the software intact in an impermeable manner from any internal or external faults. The architecture thus evolved needed a mechanism to support information processing and discovery. This necessitated the introduction of the noveI concept of infotrons. Further, when a computing machine has to perform any meaningful extraction of information, it is guided by what is termed an infotron dictionary.The other empirical study was to find out which of the two prominent markup languages namely HTML and XML, is best suited for the incorporation of infotrons. A comparative study of 200 documents in HTML and XML was undertaken. The result was in favor ofXML.The concept of infotron and that of infotron dictionary, which were developed, was applied to implement an Information Discovery System (IDS). IDS is essentially, a system, that starts with the infotron(s) supplied as clue(s), and results in brewing the information required to satisfy the need of the information discoverer by utilizing the documents available at its disposal (as information space). The various components of the system and their interaction follows the penta-tier architectural model and therefore can be considered fault-tolerant. IDS is generic in nature and therefore the characteristics and the specifications were drawn up accordingly. Many subsystems interacted with multiple infotron dictionaries that were maintained in the system.In order to demonstrate the working of the IDS and to discover the information without modification of a typical Library Information System (LIS), an Information Discovery in Library Information System (lDLIS) application was developed. IDLIS is essentially a wrapper for the LIS, which maintains all the databases of the library. The purpose was to demonstrate that the functionality of a legacy system could be enhanced with the augmentation of IDS leading to information discovery service. IDLIS demonstrates IDS in action. IDLIS proves that any legacy system could be augmented with IDS effectively to provide the additional functionality of information discovery service.Possible applications of IDS and scope for further research in the field are covered.

Studies on vibrio spp. in juveniles of penaeus indicus in culture systems

The present study is carried out to understand (i) the incidence and occurrence of species of Vibrio in different culture systems in and around Cochin, (ii) characteristics of vibrios isolates, their ecology including growth response to various hydrological parameters, sensitivity to about 40 antibiotics, and (iii) role of physico-chemical parameters in pathogenicity of vibrios, etc. and the results emerged from the investigations are important and encouraging for better understanding of the 'vibriosis' in the culture systems to develop remedial measures to control diseases. The Thesis begins with an “Introduction” followed by “A review of literature” on diseases of penaeid shrimps with particular reference to 'vibriosis' and “Material and methods” which details with the methods and procedures followed in the experiments and analyses of data. This Thesis consists of three chapters. Chapter Ideals with the incidence and ecology of Vibrio spp. in water, sediment and in juveniles of the Indian white prawn Penaeus indicus in the culture systems. In Chapter 2, characteristics of vibrio isolates including growth response to various levels oftemperature, salinity and pl 1, sensitivity to 40 antibiotics and minimal inhibitory concentration tests are detailed.e out-breaks. The Chapter 3 discusses the role of physico-chemical parameters in the incidence, seasonal abundance of Vibrio spp. and in 'vibriosis'. A summary of the whole work and list of references are also included at the end. This study gives a detailed information regarding the incidence and ecology of vibrios in the culture systems. their characteristics and pathogenicity

Studies on the universal parameters and onset of chaos in dissipative systems

It has become clear over the last few years that many deterministic dynamical systems described by simple but nonlinear equations with only a few variables can behave in an irregular or random fashion. This phenomenon, commonly called deterministic chaos, is essentially due to the fact that we cannot deal with infinitely precise numbers. In these systems trajectories emerging from nearby initial conditions diverge exponentially as time evolves)and therefore)any small error in the initial measurement spreads with time considerably, leading to unpredictable and chaotic behaviour The thesis work is mainly centered on the asymptotic behaviour of nonlinear and nonintegrable dissipative dynamical systems. It is found that completely deterministic nonlinear differential equations describing such systems can exhibit random or chaotic behaviour. Theoretical studies on this chaotic behaviour can enhance our understanding of various phenomena such as turbulence, nonlinear electronic circuits, erratic behaviour of heart and brain, fundamental molecular reactions involving DNA, meteorological phenomena, fluctuations in the cost of materials and so on. Chaos is studied mainly under two different approaches - the nature of the onset of chaos and the statistical description of the chaotic state.

Information discovery in distributed systems - A novel concept based on modelling of information elements

This thesis attempts to investigate the problems associated with such schemes and suggests a software architecture, which is aimed towards achieving a meaningful discovery. Usage of information elements as a modelling base for efficient information discovery in distributed systems is demonstrated with the aid of a novel conceptual entity called infotron. The investigations are focused on distributed systems and their associated problems. The study was directed towards identifying suitable software architecture and incorporating the same in an environment where information growth is phenomenal and a proper mechanism for carrying out information discovery becomes feasible. An empirical study undertaken with the aid of an election database of constituencies distributed geographically, provided the insights required. This is manifested in the Election Counting and Reporting Software (ECRS) System. ECRS system is a software system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous statutory reports.

Development and Validation of Bacterial Consortia for Bioremediation of Detritus in Aquaculture Systems

Cochin University Of Science And Technology

Marine Actinomycetes as Source of Antimicrobial Compounds and as Probiotics and Single Cell Protein for Application in Penaeid Prawn Culture Systems

This thesis Entitled Marine actinomycetes as source of antimicrobial compounds and as probiotics and single cell protein for application in penaeid peawn culture systems. Ocean harbours more than 80% of all life on earth and remains our greatest untapped natural resource. The study revealed the potential of marine actinomycetes as a source of antimicrobial compounds. The selected streptomycetes were found to be capable of inhibiting most of the pathogenic vibrios, whichis a major problem both in hatcheries and grow out systems. The bioactive principle can be incorporated with commercial feeds and applied as medicated diet for the control of vibrios in culture systems.The hydrolytic potential inhibitory property against pathogens and non—pathogenicity to penaeid prawns make the selected Streptomycesspp.an effective probioic in aquaculture. Since there is considerably less inhibition to the natural in pond ecosystem the microbial diversityis being maintained and thereby the water quality. Actinomycetes was found to be a good source of single cell protein as an ingredient inaquaculture feed formulations. Large amount of mycelial waste (actinomycete biomassO is produced from antibiotic industries and this nutrient rich waste can be effectively used as a protein source in aquaculture feeds.This study reveals the importance of marine actinomycetes as a source of antimicrobial compounds and as a probiotic and single cell protein for aquaculture applications.

Study on acceleratore in rubber vulcanization with special reference to the binary systems containing substituted dithiobiurets

The thesis entitled Study on Accelerators in Rubber Vulcanization with Special Reference to the Binary Systems Containing Substituted Dithiobiurets. It includes a detailed study on the binary accelerator systems containing substituted dithiobiurets in natural rubber and NR latex and dithiobiurets in SBR and NR-SBR blends vulcanization systems. It deals with the experimental procedure adopted for the preparation of DTB-II and DTB-III; the procedure for compounding and vulcanization and determination of physical properties like modulus, tensile strength, elongation at break, hardness, compression set, heat build up etc. The results indicate that there is efficient acceleration activity of the dithiobiurets in the vulcanization of natural rubber latex containing TMT. The study of dithiobiurets in natural rubber and NR latex reveal that they are having definite accelerating effect in SBR vulcanization systems.

Development of nitrifying bacterial consortia for immobilizing in nitrifying bioreactors designed for penaeid and non-penaeid larval rearing systems in the tropics

Two ammonia oxidizing (AMOPCU-1 and AMONPCU-1) and two nitrite oxidizing (NIOPCU-1 and NIONPCU-1) consortia for activating nitrifying bioreactors and thereby establishing nitrification in penaeid and non-penaeid hatchery systems were developed by enrichment. For further amplification of the consortia a simple medium having seawater (either salinity 30 ‰ or 15 ‰) as base, supplemented with NH4+-N/NO2--N and PO4- and pH adjusted to 8 was identified. During the amplification in a fermentor the consortia exhibited excessive wall growth and diminished their yield coefficient posing difficulty in harvesting the cells completely. The consortia consisted of both Gram negative and Gram-positive bacterial cells embedded in a mucilaginous matrix of glycocalyx - like material presumably composed of polysaccharides. The consortia besides being useful in activating nitrifying bioreactors developed for shrimp/prawn hatchery systems can also be used as bioaugmentors in the bioremediation of ammonia and nitrite toxicity in aquaculture systems.