Studies on the ecology of zooplankton of cochin backwaters(a tropical estuary)

Ecology is the study of systems at a level in which individuals or whole organisms may be considered elements of interaction, either among themselves, or with a loosely organised environmental matrix. Systems at this level are named ecosystems, and ecology, of course, is the biology of ecosystems" (Hargalef, 1968). This thesis includes principally, a study on the ecology of zooplankton of the Cochin backwaters conducted during the years 1971-72. This monsoonal estuarine system is particularly interesting, since it exhibits a wide range of variations in its environmental conditions which is naturally reflected in the fauna also. Several publications on various aspects of its hydrobiology have come out in the recent past. But studies on the zooplankton of the estuary have mostly been discontinuous either in space or time or restricted to its groups

Studies On The Biology Of The Clam Sunetta Scripta (Linne), From The Subtidal Waters Of Cochin

Enhancement and culture of bivalves presents an opportunity to maximise and even increase production of many growing areas. Clam culture is less intensive both for capital and labour, involves simple farming and management techniques and is considered an efficient means of protein production. Clams are efficient converters of primary production and growth rate is fast with maximum production in 5-6 months. with culture, production is less influenced by poor recruitment. Stable production facilitates market development. Rivalves are being increasingly used in bio-medical research. Culture practices would ensure uninterrupted supplies of experimental material. Paucity of biological data restricts the development of efficient management and culture techniques of bivalves. This study was undertaken with a view to provide information on some aspects of biology of the bivalve S_. scripta which have hitherto been uninvestigated.

Bionomics, Resource Characteristics And Distribution Of The Threatened Freshwater Fishes Of Kerala

The previous faunistic studies were concentrated.on the taxonomical and zoogeo— graphical aspects. These studies contributed to many new additions to the fish fauna of Kerala meanwhile many species described earlier are reported missing in recent years. Many fish species were collected only once or twice by scientists. Detailed information on distribution, habitat, feeding habits, reproduction, population size, etc. are available only with regard to a very few fish species. A meaningful assessment on the biodiversity status of the majority of freshwater fishes cannot be done for want of sufficient data base and therefore, no suitable conservation and management programmes are forthcoming for the protection and preservation of the unique fish germplasm resources of Kerala. The present study was conceptualised and undertaken mostly aiming at bridging these gaps by generating an authentic data base on the distribution, resource characteristics and bionomics of the threatened fishes inhabiting the rivers of Kerala. Osteobrama bakeri (Day) is an endemic fish having a very highly restricted and fragmented distribution in Periyar, Chalakudy, Kabini, Kallada and Meenachil rivers of Kerala. This belongs to vulnerable category and is locally known as Mullanpaval which is valued as food fish. Besides, due to its vibrant and attractive colouration and easiness for domestication, it has great potential for being propagated as an ornamental fish. Hitherto, no information is available on the bionomics and resource characteristics of this species. Studies on detailed life history traits are indispensable for fishery management, development of captive breeding technique and implementation of various conservation programmes. In the present study, a pioneer attempt is also made to investigate the life history traits, resource characteristics, proximate composition, etc. of O.baken'.

Fabrication And Parametric Measurements Of N2 Laser Pumped Dye Laser And Its Application To Energy Transfer Studies In Mixed Dyes

Eventhough a large number of schemes have been proposed and develoned for N9 laser ouined dye lasers the relatively low efficiency compelled the scientists to device new methods to improve the system efficiencs. Energy transfer mechanism has been shown to he a convenien tool for the enhancement of efficiency of dye lasers. Th p resent work covers a detailed study of the performance characteristics of a N2 laser pumped dye laser in the con— ventional mode and also, when pumped by the energy transfer mechanism. For .th.e present investigations a dye laser pumped by a'N2 laser (A4200 kw peak power) was fabricated. The grating at grazing incidence was used as the beam expanding device; A t its best performance the system was giving an output peak power of l5 kW for a 5 X lC"3H/l Rh—€ solution in methanol. T he conversion efficiency was 7.5; The output beam was having 3 divergence of 2 mrad and bandwidth o.9 A. Suitable modifications were suggested for obtaining better conversion efficiency and bandwidth.

Problems And Prospects Of Marketing Indian Cardamom At Home And Abroad

The main objective of the study has been to analyse the marketing problems of Indian cardamom at home and abroad and examine possible courses of action which would lead to increased consumption of cardamom, both within India and abroad. This has been done in the context of the anticipated increases in the Indian and world supply of cardamom. Field studies were undertaken to understand the cost of production of cardamom and cost of export. This study was also directed at examining how far price fluctuations in cardamom can be controlled in the Indian context, so as to have a reasonable and stable income for primary producers which will ensure adequate encouragement for higher production and better export earnings.

Surface electron properties and catalytic activity of rare earth oxides

The rare earths have provided fascinating field for chemists confronted with problems of their separation and purification. The rare earths become available in relatively pure form in recent years due to the development of efficient separation methods, largely as a byproduct of the atomic energy programmes of various countries. The rare earths often called lanthanides from La (Z=57) to Lu (Z=7l) display subtle variation of properties through the series, while the differences become appreciable for the elements that are farther apart.

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

Preparation of useful raw materials from Refinery sludge and its utilisation in rubber processing

Petroleum, a mixture of organic compounds, comes from underground rock formations ranging in age from ten to several hundred million years. The process by which it is formed and developed is not yet completely known. Studies indicate that petroleum is formed mainly from microscopic-sized marine animals and plants. When these organisms died in water of low oxygen content, they did not decompose. Thus their remains sank to the bottom to be buried under accumulations of sediment. Their conversion to petroleum remains a subject of research even today.

Glutamatergic Nmda And Ampa Receptors Functional Regulation In Streptozotocin Induced Diabetic Rats: Effect Of Vitamin D3 And Curcumin Supplementation

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.

Studies On The Synthesis Of Vitamin A And Related Compounds

In the present work different new approaches for the synthesis of Vitamin A are investigated. In these synthetic schemes, all the twenty carbon atoms of the target molecule are derived either fully from components isolated from common essential oils or partially from commercially available materials. By retrosynthetic analysis, Vitamin A molecule can be disconnected into a cyclic and a linear unit. Different methods for the synthesis of the linear and the cyclic components are described. The monoterpenes, geraniol and citral, major constituents of palmarosa and lemongrass oils, have the required basic carbon framework for consideration as starting materials for the synthesis of Vitamin A. The potential of these easily available naturally occurring compounds as promising starting materials for Vitamin A synthesis is demonstrated. Organoselenium and organosulfur mediated functional group transformations for the synthesis of the functionalised conjugated C10 linear components (ie., the dimethyloctatriene derivatives) are reported. The classical approaches as well as the attempted preparation of cyclic C10 and C13 units employed in the present study as intermediates for Vitamin A synthesis are described. The utility of commercially available materials namely 2-acetylbutyrolactone and levulinic acid in -the preparation of C5 intermediates for Vitamin A synthesis is demonstrated.

Population Biology And Ecology Of Artemia From Salinas Of South East Coast Of India

This thesis deals with the population characteristics of Artemia and the effect of different environmental parameters on the different stages of Artemia in a salina at Tuticorin, south east coast of India. The present investigation was carried out from 1985 to I987. The study was initiated by undertaking a survey to find out suitable Artemia habitats along the south east coast of India and a perennial salina with an area of 0.25 ha was selected at Karapad (Tuticorin). Weekly samplings were made for two full calender years (1986-87) to collect the different stages of Artemia population as well as the different environmental parameters. The thesis comprises of the following sections: Introduction, materials and methods, systematics, biology and distribution of Artemia, results and discussion, summary and bibliography. The section on results and discussion gives the characteristics of Artemia population in the salina, the seasonal variations of different environmental parameters in the salina and their effects on different stages of Artemia population. Description of an experiment conducted to show the sudden changes of salinity on different stages of Artemia is also given as a separate section.

Production of latex reclaim and its utilisation in polymer blends

The overall objective of the present study was to develop a novel and economic reclaiming process that does not adversely affect the quality of rubber and to investigate methods of utilising the reclaim. Since waste latex products represent a potential source of high quality rubber hydrocarbon, it was decided to develop a process based on such latex wastes. The study revealed that latex reclaim could replace raw natural rubber upto about 50 per cent of its weight without any serious deterioration in mechanical properties.

Studies on some fish larvae of the arabian sea and bay of bengal

Though several scientific expeditions surveyed tha Indian ocean. their findings on larval fishes were fragmentory and incomplete. During the International Indian ocean expedition (1960-1965) zooplankton samples were collected from vast area at the lndian ocean adopting standard procedures by participating vessels. These planktons provided an opportunity for a general study of the zooplanltton as well as their anotomy. abundance and distribution.. Realising the imortance of the analysis and classification of fish larvae at the family level being one of the most important information required then for the Indian Ocean region the fish larval portion sorted out from the above zooplankton samples was allocated to the author by the UNESCO consultative committee for the Indian Ocean Biological centre. In spite of the emhasis laid on The study of the family scombridae. owing to the paucity of the scombridae material in tne collection. much could not be done about it.However the record and description of the very early stages of morakel larvae made in 1967 as part of this study was the first of its kind. The present study on the distribution aspects o fish larva of such large area in the Indian ocean is also unique and first of its kind

Synthesis, characterization and properties of Conductive elastomeric composites based on Polypyrrole and short Nylon-6 fiber

The search for new materials especially those possessing special properties continues at a great pace because of ever growing demands of the modern life. The focus on the use of intrinsically conductive polymers in organic electronic devices has led to the development of a totally new class of smart materials. Polypyrrole (PPy) is one of the most stable known conducting polymers and also one of the easiest to synthesize. In addition, its high conductivity, good redox reversibility and excellent microwave absorbing characteristics have led to the existence of wide and diversified applications for PPy. However, as any conjugated conducting polymer, PPy lacks processability, flexibility and strength which are essential for industrial requirements. Among various approaches to making tractable materials based on PPy, incorporating PPy within an electrically insulating polymer appears to be a promising method, and this has triggered the development of blends or composites. Conductive elastomeric composites of polypyrrole are important in that they are composite materials suitable for devices where flexibility is an important parameter. Moreover these composites can be moulded into complex shapes. In this work an attempt has been made to prepare conducting elastomeric composites by the incorporation of PPy and PPy coated short Nylon-6 fiber with insulating elastomer matrices- natural rubber and acrylonitrile butadiene rubber. It is well established that mechanical properties of rubber composites can be greatly improved by adding short fibers. Generally short fiber reinforced rubber composites are popular in industrial fields because of their processing advantages, low cost, and their greatly improved technical properties such as strength, stiffness, modulus and damping. In the present work, PPy coated fiber is expected to improve the mechanical properties of the elastomer-PPy composites, at the same time increasing the conductivity. In addition to determination of DC conductivity and evaluation of mechanical properties, the work aims to study the thermal stability, dielectric properties and electromagnetic interference shielding effectiveness of the composites. The thesis consists of ten chapters.

Molecular breakdown of different forms of natural rubber and its influence on properties of their mixes and vulcanizates

The forms of natural rubber studied were sheet [RSS 4 and RSS 5], ISNR 20 and EBC. In the case of the latter two forms samples from estate and nonestate sectors were included. The samples were collected from different locations at specified intervals, for a particular period. The effect of the extent of mastication on raw rubber properties as well as the properties of the compounds and vulcanizates also studied. The consistency in raw rubber properties and breakdown behavior of skim rubber were studied by collecting samples periodically from selected processing units. The effect of incorporation of skim with ISNR 20 has also been investigated