| Abstract: | Organic molecules with π-conjugated scaffolds end-capped with electron donor and acceptor groups are widely investigated due to their immense application potentials and hence belong to a promising area of organic chemistry. Donor-acceptor materials have found wide variety of applications such as dyes in dye-sensitised solar cells (DSSCs), organic photovoltaics, organic light emitting diodes, nonlinear optical devices, chemosensors, diagnostic probes and as therapeutic agents. Despite their use in such a wide range of applications, many fundamental properties of donor acceptor materials are still poorly understood. Even simple structural modifications can bring unexpected electronic and photophysical properties and wider understanding of the interaction between donor and acceptor is thus required. Furthermore, many such systems show diversity in properties in solution state or in their condensed state such as crystalline or amorphous forms. For example, some of these molecules show aggregation induced quenching or enhancement in emission in the solid state. Thus, structural motifs that facilitate intermolecular interaction via hydrophobic association, hydrogen bonding or electrostatic effects can lead to excellent control over their supramolecular functions. Some of the important structural types which used as donors are triarylamines, carbazoles, phenothiazine, fluorenes, thiophenes, and oligothiophenes. Strongly electron withdrawing groups or electron deficient heterocyclic systems such as oxadiazoles, diarylborons, quinolines, quinoxalines, thienopyrazines, and benzothiadiazoles, cyanoacetic acid, rhodanine-3-acetic acid, barbituric acid, and thiobarbituric acid etc., have been used as the acceptors in the design of donor-acceptor systems. |
| URI: | http://dyuthi.cusat.ac.in/purl/5141 |
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| Dyuthi-T2175.pdf | (11.47Mb) |
| Abstract: | A detailed survey of the present knowledge on the physical aspects of the mud banks has been presented in chapter 1.The physical geographical and geological aspects of the kerala coast, the shore-line and the sea bed and the various views on the formation,movements and dissipation of the mud banks have been discussed.The scope of the present work and a description of the area of study have also been given in this chapter. The horizontal and vertical distribution and the seasonal variations of the concentration of suspended matter in the mud bank region are discussed in chapter 3.it is seen that the mud bank reses above the bottom in the form of a ridged ,irregular,solid come with a flat top. Chapter vi deals with waves and currents in the region of the mud bank. The orientation of the breakers on either side of the mud bank suggests the possibility of formation of opposing alongshore currents and convergence of energy caused by wave refraction.The distribution of currents during the formative nature and dissipating stages of the mud bank show that the converging alongshore currents give rise to offshore flows |
| Description: | School of Marine Science, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3145 |
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| Dyuthi-T1119.pdf | (5.215Mb) |
| Description: | Division of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/xmlui/purl/2056 |
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| Dyuthi-T0473.pdf | (4.646Mb) |
| Abstract: | Penaeid prawns form the most economically significant group in the marine and brackishwater fishery resources of India. This particular group contributes about 62% of the total prawn landings of the country. At present prawns have assumed an important place especially as a commodity supporting an export trade of sizable magnitude. Considerable interest has been shown in the last decade to increase prawn production through various culture practices, mainly due to the high demand for good quality prawns for export coupled with the stagnant and even depleting nature of marine catches. Available informations suggest that among the 15 species of shrimps and prawns occurring in Indian waters, which are deemed suitable for aquaculture, the Indian white prawn §.indicus is identified as one of the most important commercial species. Considering the increasing importance as an accepted species for prawn culture, £.indicus was selected for the present study. In the life history of prawns, moulting is an important event, which enables the animal to achieve growth. This dynamic physiological event continues through out the life span ofthe prawn, linking almost all biological activities with this process. Hence, a good knowledge pertaining to the physiology of moulting is imperative to understand the growth process. This knowledge will be of great use in the scientific prawn farming, so as to achieve high prawn production. |
| Description: | School of marine sciences, Central institute of fisheries technology, Cochin University of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3437 |
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| Dyuthi-T1403.pdf | (6.680Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1237 |
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| Vijayan K K 1989.PDF | (679.7Kb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1148 |
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| Gopinathan C P 1983.PDF | (178.3Kb) |
| Abstract: | The main purpose of the Study is to outline the main distributional features of the species of the calonoid copepod family seolecithricidae in the Indian Ocean Expedition collections and to distinguish and describe their niches. In the present thesis 27 species belonging to 7 genera were identified of which 2 were new records from the Indian Ocean and one was described as a new species. In addition to the general treatment of the taxonomy, zoogeography and species diversity in relation to various environmental parameters are also attempted |
| Description: | National institute of Oceanography |
| URI: | http://dyuthi.cusat.ac.in/purl/3168 |
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| Dyuthi-T1142.pdf | (13.58Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1147 |
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| Gopalakrishnan T C 1982.PDF | (670.6Kb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5229 |
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| Dyuthi T-2264.pdf | (1.889Mb) |
| Description: | Dept.of Applied Chemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2157 |
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| Dyuthi-T0516.pdf | (7.090Mb) |
| Abstract: | Algal blooms are naturally occurring phenomena in the aquatic environment. These blooms cause mass mortalities of wild and farmed fish and shellfish, human intoxications which sometimes result in death, alteration of marine trophic structure through adverse effects on larvae and other life history stages of commercially important species and death of marine animals. Occurrences of harmful algal blooms and associated mortality have been reported along the coastal waters of India since the early period of the last century. The present study was taken up to study the dynamics of major phytoplankton blooms, which occur along the Kerala coast. The results of quantitative and qualitative analysis of phytoplankton in the coastal waters of Vizhinjam and Chombala, their species diversity and community structure is presented and the major algal blooms recorded along the coast of Kerala during the study period is described and their occurrence is related to the hydrographic and meteorological variations. There is a clear evident from these works in the Indian region that the fishes avoid areas where these harmful algae bloom, either due to the toxicity or due to some irritant property of the chemicals secreted by the algae. Taxonomic diversity studies indicated a change in the community structure of commercial finfishes, crustaceans and molluscs due to the bloom of C.marina and funnel plots indicated the deviation in taxonomic distinctness during the bloom period from theoretical mean for the region. |
| URI: | http://dyuthi.cusat.ac.in/purl/973 |
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| Dyuthi-T0359.pdf | (13.29Mb) |
| Abstract: | This thesis deals with the results of investigations on primary production and related aspects conducted in the Indian seas since 1957 and includes the regional and seasonal variations in the rate of production factors controlling the same and the magnitude of potential fishery resources derived from it. Data collected for various periods using oxygen and 14c techniques from the Gulf of Mannar, palk bay, the south west coast of India including laccadive sea together with other available data form the basis of these studies. |
| Description: | Central Marine Fisheries Research Institute |
| URI: | http://dyuthi.cusat.ac.in/purl/3321 |
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| Dyuthi-T1317.pdf | (12.79Mb) |
| Abstract: | Kerala was the pioneer in modern seafood processing and exporting. But now the industry is Iacingalot of problems due to low productivity and deterioration in the quality of the products. only about 17% of the installed freezing capacity in sea food processing industry was reported to be utilised during 1979-80. The price of the export commodities its decided by the buyers based on international supply and demand pattern and based on the strength and weakness of dollar/yen. The only way to increase the profitability of the processors is to reduce the cost of production to the possible extent. The individual processors find it difficult to continue in this field due to low productivity and quality problems. The main objectives of the research are to find out how the production is being managed in the seafood processing(freezing) 17industry in Kerala and the reasons for low productivity and poor quality of the products. The study includes a detailed analysis of Location of the factories. Layout Purchase, production and storage patterns. Production planning and scheduling. Work Measurement of the processing of important products. Quality Control and Inspection. Management Information System |
| Description: | Department of Industrial fisheries, Cochin University of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3584 |
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| Dyuthi-T1591.pdf | (6.421Mb) |
| Abstract: | Latex protein allergy is a serious problem faced by users of natural rubber latex products. This is severe in health care workers, who are constantly using latex products like examination gloves, surgical gloves etc. Out of the total proteins only a small fraction is extractable and only these proteins cause allergic reactions in sensitized people. Enzymic deproteinisation of latex and leaching and chlorination of latex products are the common methods used to reduce the severity of the problem.Enzyme deproteinisation is a cubersome process involving high cost and process loss.Physical properties of such films are poor. Leaching is a lengthy process and in leached latex products presence of extractable proteins is observed on further storing. Chlorination causes yellowing of latex products and reduction in tensile properties.In this context a more simple process of removal of extractable proteins from latex itself was investigated. This thesis reports the application of poly propylene glycol (PPG) to displace extractable proteins from natural latex. PPG is added to 60 % centrifuged natural latex to the extent of 0.2 % m/rn, subssequently diluted to 30 % dry rubber content and again concentrated to obtain a low protein latex.Dilution of concentrated latex and subsequent concentration lead to a total reduction in non - rubber solids in the concentrate, especially proteins and reduction in the ionic concentration in the aqueous phase of the latex. It has been reported that proteins in natural rubber / latex affect its behaviour in the vulcanisation process. Ionic concentration in the aqueous phase of latex influence the stability, viscosity and flow behaviour of natural latex. Hence, a detailed technological evaluation was carried out on this low protein latex. In this study, low protein latex was compared with single centrifuged latex ( the raw material to almost every latex product), double centrifuged latex ( because dilution and second concentration of latex is accompanied by protein removal to some extent and reduction in the ionic concentration of the aqueous phase of latex.). Studies were conducted on Sulphur cure in conventional and EV systems under conditions of post ~ cure and prevulcanisation of latex. Studies were conducted on radiation cure in latex stage. Extractable protein content in vulcanised low protein latex films are observed to be very low. lt is observed that this low protein latex is some what slower curing than single centrifuged latex, but faster than double centrifuged latex. Modulus of low protein latex films were slightly low. In general physical properties of vulcanised low protein latex films are only siightly lower than single centrifuged latex. Ageing properties of the low protein latex films were satisfactory. Viscosity and flow behaviour of low protein latex is much better than double centrifuged latex and almost comparable to single centrifuged latex. On observing that the physical properties and flow behaviour of low protein latex was satisfactory, it was used for the preparation of examination gloves and the gloves were evaluated. It is observed that the properties are conforming to the Indian Standard Specifications. It is thus observed that PPG treatment of natural latex is a simple process of preparing low protein latex. Extractable protein content in these films are very low.The physical properties of the films are comparable to ordinary centrifuged latex and better than conventionally deprotenized latex films. This latex can be used for the production of examination gloves. |
| Description: | Rubber Research Institute |
| URI: | http://dyuthi.cusat.ac.in/purl/3130 |
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| Dyuthi-T1104.pdf | (6.697Mb) |
| Abstract: | 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. |
| Description: | School of marine sciences, Cochin University of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3346 |
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| Dyuthi-T1305.pdf | (7.288Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1168 |
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| Neelakandan Namboodiripad K S 1984.PDF | (436.5Kb) |
| Abstract: | In this study the quality and process control factors during the production and storage of salted dried fish products. The study reveals that quantity of dry fish production in the state is decreasing and dry fish processing industry should be encouraged by central and state governments. The dry and wet salting may be carried out to a period of 4 to 8 hours respectively and time may depend on temperature, size, and concentration of medium. Demand is an unavoidable factor for sale of fish. The packed dry salted lots kept at room temperature are useful only for 20 days. The refrigerator- stored lots had more storage life and nutritional content are good up to 3 months. The cold storage stored dry salted lot had more storage life than the wet salted lot. The use of preservatives in salting is encouraged to reduce pH. The low temperature preservation maintains the nutritional value and quality for long period. It further encourages the labeling of nutritional value of dry fish as in tinned products. |
| URI: | http://dyuthi.cusat.ac.in/purl/87 |
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| Dyuthi-T0254.pdf | (13.47Mb) |
| Abstract: | The present study focused on the quality of rainwater at various land use locations and its variations on interaction with various domestic rainwater harvesting systems.Sampling sites were selected based upon the land use pattern of the locations and were classified as rural, urban, industrial and sub urban. Rainwater samples were collected from the south west monsoon of May 2007 to north east monsoon of October 2008, from four sampling sites namely Kothamangalam, Emakulam, Eloor and Kalamassery, in Ernakulam district of the State of Kerala, which characterized typical rural, urban, industrial and suburban locations respectively. Rain water samples at various stages of harvesting were also collected. The samples were analyzed according to standard procedures and their physico-chemical and microbiological parameters were determined. The variations of the chemical composition of the rainwater collected were studied using statistical methods. It was observed that 17.5%, 30%, 45.8% and 12.1% of rainwater samples collected at rural, urban, industrial and suburban locations respectively had pH less than 5.6, which is considered as the pH of cloud water at equilibrium with atmospheric CO,.Nearly 46% of the rainwater samples were in acidic range in the industrial location while it was only 17% in the rural location. Multivariate statistical analysls was done using Principal Component Analysis, and the sources that inf1uence the composition of rainwater at each locations were identified .which clearly indicated that the quality of rain water is site specific and represents the atmospheric characteristics of the free fall The quality of harvested rainwater showed significant variations at different stages of harvesting due to deposition of dust from the roof catchment surface, leaching of cement constituents etc. Except the micro biological quality, the harvested rainwater satisfied the Indian Standard guide lines for drinking water. Studies conducted on the leaching of cement constituents in water concluded that tanks made with ordinary portland cement and portland pozzolana cement could be safely used for storage of rain water. |
| Description: | School of Engineering, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2123 |
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| Dyuthi-T0474.pdf | (4.023Mb) |
| Abstract: | From the point of view of rational exploitation and proper management of the fishery resources as well as for the development of intensive aquaculture of fishes through selective breeding, brood stock development, domestication and genetic improvement, a sound knowledge of reproductive biology and physiology of the candidate species is of great importance. In recent times, a wealth of information on maturity, spawning habits, spawning periodicity, spawning season, size at maturity and fecundity of commercially important fishes has been generated. Gametogenesis involves the transformation of Primordial germ cells in the gonads into specialised cells or gametes, namely ova in the female and sperms in male, through a series of complex morphological and cytological events. The formation of male gamete is known as spermatogenesis. In the female, the primary growth phase involving the formation of primary oocyte from oogonia is known as oogenesis, which would be followed by the secondary growth phase, in which considerable increase in the size of the oocyte occurs, due mainly to accumulation of yolk. This process is known as vitellogenesis, which would be followed by final maturation and ovulation of the ova. In the present work, basic aspects of maturation and spawning, salient features of gametogenesis and associated biochemical changes occurring during these processes in an important cultivable fish, Sillago sihama belonging to the family Sillaginidae have been investigated. |
| Description: | Department of Marine Sciences,Cochin University Of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3767 |
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| Dyuthi-T1728.pdf | (7.364Mb) |
| Abstract: | The present investigation has been carried out to understand the process and events leading to maturation of the ovary and testis in the Indian white prawn Penaeus indicus. The study includes the classification of the ovarian maturity stages based on its colour, gonadosomatic index, oocyte diameter and morphological changes in the oocyte. Further the process of oogenesis has been investigated using light and electron microscopic techniques. A histochemical study of the ovary has also been carried out to determine the sequence in which yolk substances are synthesized or sequestered in the oocytes and also to elicit the nature of the penaeid yolk material. The process of spermatogenesis and the development of the spermatophore has been studied in detail using light and electron microscopic methods. In addition a brief histochemical study on the testis was also made to understand the nature of the organic reserves in the sperm cells. |
| Description: | Centre of Advanced Studies in Mariculture, Central Marine Fisheries Research Institute |
| URI: | http://dyuthi.cusat.ac.in/purl/3234 |
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| Dyuthi-T1208.pdf | (5.814Mb) |
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