Anil Kumar,K G; Dr.Viswanadham,D V(Cochin University of Science and Technology, March , 1986)
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Abstract:
Pollutants that once enter into the earth’s atmosphere become part of the atmosphere and hence their dispersion, dilution, direction of transportation etc. are governed by the meteorological conditions. The thesis deals with the study of the atmospheric dispersion capacity, wind climatology, atmospheric stability, pollutant distribution by means of a model and the suggestions for a comprehensive planning for the industrially developing city, Cochin.
The definition, sources, types and effects of air pollution have been dealt with briefly. The influence of various meteorological parameters such as vector wind, temperature and its vertical structure and atmospheric stability in relation to pollutant dispersal have been studied. The importance of inversions, mixing heights, ventilation coefficients were brought out. The spatial variation of mixing heights studies for the first time on a microscale region, serves to delineate the regions of good and poor dispersal capacity. A study of wind direction fluctuation, σθ and its relation to stability and mixing heights were shown to be much useful. It was shown that there is a necessity to look into the method of σθ computation. The development of Gausssian Plume Model along with the application for multiple sources was presented. The pollutant chosen was sulphur dioxide and industrial sources alone were considered.
The percentage frequency of occurrence of inversions and isothermals are found to be low in all months during the year. The spatial variation of mixing heights revealed that a single mixing height cannot be taken as a representative for the whole city have low mixing heights and monsoonal months showed lowest mixing heights. The study of ventilation co-efficients showed values less than the required optimum value 6000m2/5. However, the low values may be due to the consideration of surface wind alone instead of the vertically averaged wind.
Relatively more calm conditions and light winds during night and strong winds during day time were observed. During the most of the year westerlies during day time and northeasterlies during night time are the dominant winds.
Unstable conditions with high values of σθ during day time and stable conditions with lower values of σθ during night time are the prominent features. Monsoonal months showed neutral stability for most of the time. A study σθ of and Pasquill Stability category has revealed the difficulty in giving a unique value of for each stability category. For the first time regression equations have been developed relating mixing heights and σθ. A closer examination of σθ revealed that half of the range of wind direction fluctuations is to be taken, instead of one by sixth, to compute σθ.
The spatial distribution of SO2 showed a more or less uniform distribution with a slight intrusion towards south. Winter months showed low concentrations contrary to the expectations. The variations of the concentration is found to be influenced more by the mixing height and the stack height rather than wind speed. In the densely populated areas the concentration is more than the threshold limit value. However, the values reported appear to be high, because no depletion of the material is assumed through dry or wet depositions and also because of the inclusion of calm conditions with a very light wind speed.
A reduction of emission during night time with a consequent rise during day time would bring down the levels of pollution. The probable locations for the new industries could be the extreme southeast parts because the concentration towards the north falls off very quickly resulting low concentrations. In such a case pollutant spread would be towards south and west, thus keeping the city interior relatively free from pollution. A more detailed examination of the pollutant spread by means of models that would take the dry and wet depositions may be necessary. Nevertheless, the present model serves to give the trend of the distribution of pollutant concentration with which one can suggest the optimum locations for the new industries
Description:
School of Marine Sciences, Cochin University of Science and Technology
Arul,James M; Dr.Samuel, C T(Cochin University of Science and Technology, May , 1983)
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Abstract:
This thesis deals initially with a literature reference survey ,taxonomy, their incidence in selected food fishes and shellfishes, and their incidence and distribution, their survival during different types of processing, their heat survival at temperatures of 50 ,55 and 60 degree centigrade their growth initiation at different low levels of pHs(4.0 to 10) ,and their developmental resistance to various chemical agents. The trials for the study were collected from various landing centre at cochin and the retail outlets. Based on these data collections the researcher was able to obtain more knowledge of the processing technology and the survival of pathogens like salmonella and vibrio parahaemolyticus.
Chandrasekaran, M; Dr.Lakshmanaperumalsamy, P; Dr.Chandramohan, D(Cochin University of Science and Technology, April , 1985)
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Abstract:
The aim of the present investigation is to build up the knowledge on the role of commensal bacteria present on the prawns during storage at various temperatures. The study Evaluates the nature of spoilage of prawns during storage at three different temperatures (28:2OC, 4°C and -18°C) by organoleptic assessment, accumulation of trim ethylamine, ammonia content, changes in the flesh pH and total heterotrophic bacterial population at various time intervals and to find out the changes in the proximate composition (protein, carbohydrate, lipid, ash and moisture) of the prawns during storage at various temperatures by estimating the contents at different time intervals along with spoilage assessment. The researcher studies the occurrence and role of various bacterial genera which form the component of spoilage flora during storage and determines the distribution of various hydrolytic enzyme producing bacteria by evaluating their ability to produce enzymes such as caseinase, gelatinase, amylase, lipase and urease. to assess the spoilage potential of the bacteria by testing their ability to reduce trimethylamine oxide (TMAO) to trimethylamine (TMA) and to produce odour in flesh broth and halos in flesh agar media.The researcher also gives stress on the growth kinetics of selected potential spoilers by growing_them in different media and to assess the effect of sodium chloride concentrations, temperature and pH on their growth, survival and. generation time.
Description:
School of Marine Sciences, Division of marine biology, microbiology and biochemistry, Cochin University of Science and Technology
Sajan,K; Dr.Damodaran, K T(Cochin University of Science And Technology, August , 1988)
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Abstract:
This study enfolds the environment of
deposition and the lateral variation in texture,
mineralogy and geochemistry of the Ashtamudy lake
sediments. While the heavy mineral and clay mineral
investigations enable us to decipher the nature, texture
and source of sediments; organic matter and carbonate
contents and the geochemical analysis of major and minor
elements help establish the distribution and
concentration of the same in regard to the various
physico-chemical processes operating in the lake.
Study of trace elements holds prime importance in
this work, since their concentrations can be used to
outline the extent of contaminated bottom area, as well as
the source and dispersal paths of discharged_pollutants.
In short, this study brings out a vivid picture of the
mineralogy and geochemistry of the lake sediments
in different environments, viz., the freshwater, brackish
water and marine environments that are confined to
the eastern, central and western parts of the lake
respectively. For the better understanding and
expression of the results of the analysis, the lake
has been divided into 3 zones namely: eastern part,
central part and western part.
Description:
School of Marine sciences, Cochin University of Science And Technology
Sophy,John T; Dr.Shahul,Hameed M(Cochin University of Science And Technology, April , 1989)
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Abstract:
Detailed information on the biology of fishes is an essential
prerequisite for their proper conservation, management and
exploitation. An amplified knowledge on the biology isfundamentally
essential to plan sound management policies for rational utilization
of Nemipterid fishes along the Indian coast. Any information on the
biochemical composition of fishes will be of immense use in assessing
their nutritive value. The importance of understanding body
composition during growth is essential in production studies.
Detailed work on Nemipterid fishes has been done in other parts of
the world whereas along the Indian coast_ not much work has been
carried out. Hence the present investigation is undertaken on the
systematics of Nemipterids available at Cochin and the biology and
biochemical aspects of_N. jagonicus and_M. mesogrion
Description:
Department of Industrial Fisheries, Cochin University of Science And Technology
Anirudhan,T S; Dr.Nambisan, P N K(Cochin University of Science and Technology, September , 1988)
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The study focuses attention on the nutrient chemistry of a tropical estuary namely the cochin estuary.The investigation was planned with the objective of studying the estuarine nutrient behaviour and to assess the role of biogeochemical cycling. The distribution of parameters of interest are better explained in the light of the hydrography of the region . Largely associated with the pollution problems of Cochin estuary receiving industrial and domestic wastes, this thesis projects the role of environmental parameters modifying the nutrient content of the water body coupled with studies on their minute variability subjected to physical, chemical and biological processes. The study has incorporated parameters like temperature, salinity, pH and D0; nutrients were investigated by the study of nitrite, nitrate. ammonia, inorganic reactive phosphorus, dissolved organic phosphorus, particulate reactive phosphorus, total reactive
phosphorus and inorganic reactive silicate-silicon at surface and bottom layers of the estuary. Sediment associated interstitial and adsorbed phosphorus for a period of one year (1985-1986] were also incorporated
Description:
Chemical Oceanography Division, School
of Marine Sciences, Cochin University of Science and Technology
Anu, Simon; Dr.Mohanakumar,K(Cochin University of Science and Technology, March 21, 1996)
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The intention of the present thesis work is to understand the physical processes responsible for climatic variability and predictability of the Indian subcontinent. The study is expected to delineate and emphasize the various boundaries and areas of transition and bring out the regional and temporal characteristics of the meteorological distribution of the country. The results obtained from the study is expected to provide a better understanding the physics of Indian cl imate, which can be incorporated for numerical weather prediction. The results obtained from the present study can be incorporated for climate modelling and long-term prediction of the meteorological parameters over Indian subcontinent
Description:
Department of Atmospheric Sciences,
Cochin University of Science and Technology
Sait, Sahul Hameed A; Dr.Vedavyasa, Rao P(Cochin University of Science and Technology, July , 1989)
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Abstract:
The thesis presents the results of the studies carried out on certain diseases encountered in the larvae and postlarvae of penaeid prawns raised in the hatcheries at Cochin, Madras and Mandapam Camp during September 1985- April 1988. In the preliminary survey carried out to understand the common diseases occurring in the penaeid larvae and postlarvae, seven cases of diseases and abnormalities were encountered. These included ciliate infestation, Nit_zschia closteriurn infestation, parasitic protozoaninfection, parasitic dinoflagellate infection, appendage necrosis, heteromorphic eye and abnormal eggs and deformed nauplii .The clinical signs, seasonal occurrence and incidence of each of the above cases were provided along with the information on environmental factors such as salinity, dissolved oxygen, temperature and pH of the rearing medium. The Thésis is presented in nine chapters. Chapter 1 surveys the literature on the diseases of penaeid larvae, postlarvae and adult prawns from India and abroad. This is followed by a chapter on the material and methods employed during the present investigation. In the third chapter, seven cases of diseases and abnormalities encountered in the larvae and postlarvae of Penaeus indicus and p. semisulcatus during the survey carried out in the hatcheries located at different centres of Central‘ Marine Fisheries Research Institute are presented and discussed .A bacterium responsible for appendage necrosis was isolated and its taxonomy was studied. It was Gram-negative, fermentative and motile rod. It was sensitive to vibriostatic compound, 0/129. This bacterium was found to be a new isolate of vibrio on the basis of its morphological, biological, physiological and biochemical characters and comparison of these characters with those described for other related vibrios. This new isolate of vibrio was deposited in vibro Referrence Laboratory, Centres for Disease Control, Georgia, U.S.A. and coded as vibrio sp. 2448-88.
Gopalakrishna Kurup, P; Dr. Varadachari, V V R(Cochin University of Science and Technology, December , 1975)
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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
Vijayan, K K; Dr.Diwan, A D(Cochin University of Science And Technology, November , 1988)
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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
Gopalakrishnan,T C; Dr.Kurian, C V(Cochin University of Science and Technology, June , 1982)
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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