Jayasankar, P; Dr.Alagarswami, K(Cochin University Of Science And Technology, June , 1989)
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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
Sunilkumar, Mohamed K; Dr.Diwan, A D(Cochin University of Science and Technology, June , 1989)
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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
Kuldeep, Lal Kumar; Dr.James, P S B R(Cochin University of Science And Technology, July , 1991)
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Abstract:
At present, there is paucity of information regarding the breeding
biology, especially from southeastern region, which differs in its climatic
features from northeastern coastal areas, where some attempts have been
made to study the biology of the fish, though not documented in detail
(Jhingran and Natarajan, I969; Patnaik and Jena, 1976; Kowtal, 1977; Roy
e_t _a_l_., I977). The present work, first to undertake detailed investigation
into reproductive aspects of the fish from India is not only confined to
biology, but extend to the study on histological as well as physiological
changes in the processes associated with natural reproductive cycle. The
main objective of the study is to develop a background for the standardisation
of subsequent artificial propagation techniques for the Sea Dass
The thesis is presented in three chapters. The first chapter; general introduction, surveys the literature pertaining to the status of research on Lates calcarifer with specific reference to reproduction and acquaculture. The second chapter entitled, materials and methods gives description regarding collection of specimens as well as samples in addition to the various analytical methodologies employed during the study.
Description:
School of marine sciences, Central institute of fisheries technology, Cochin University of Science And Technology
Sivachandrabose, K; Dr.Suseelan, C(Cochin University of Science and Technology, October 10, 1995)
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Abstract:
A study of the reproductive physiology of P. (P). semisulcatus wasundertaken as this information is an essential prerequisite for brood stock development for hatchery operations, and the results are embodied in this thesis. The thesis is presented in seven chapters. The protein, lipid and carbohydrate contents of ovary were estimated for the different vitellogenic phases. The protein, lipid, carbohydrate and cholesterol contents were estimated in testes and spermatophore.The thesis present the results of induced maturation experiments by eyestalk ablation, CNS extract injection and UV rays application on immature female prawns.
Latex waste products contain rubber hydrocarbon of very high
quality, which is only lightly cross linked. Selected wastes such as thread waste
and glove waste were modified into processable materials by a novel economic
process and thermoplastic elastomers were prepared by blending these modified
waste materials with high density polyethylene in various proportions. The
mechanical properties as well as the rheological behaviour of these blends were
evaluated and compared with those of the natural rubber-high density
polyethylene blends.
Murthy,P G K; Dr.Sharma,G S(Cochin University of Science and Technology, October , 1986)
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Abstract:
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.
Latex waste like glove waste was effectively modified using a new reclaiming
agent, thiocarbanilide. This modified waste was blended with linear low-density
polyethylene (LLDPE) to develop a novel thermoplastic elastomer. Both uncrosslinked
and dynamically crosslinked blends were prepared and their properties
were studied. The results were found to be comparable to those of conventional
thermoplastic elastomers.
Ivy, Mathew; Dr.Joseph,Francis D(Cochin University Of Science And Technology, August 20, 1992)
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Abstract:
Thermoplastic elastomers are a relatively new
class of materials which compete with thermoset rubbers in
some areas and thermoplastic materials in other areas. The
main thrust of the present investigation is a comparative
study’ on commercially .available triblock. styrene thermoplastic
elastomers and those derived from blends of
acrylonitrile-butadiene rubber and poly(vinyl chloride).
The styrene—based thermoplastic elastomers are gaining
acceptance as a replacement for both natural and synthetic
rubber‘ in many‘ applications. TPEs based on blends of
elastomers and plastics ix: the fastest growing segment of
the broad class of thermoplastic elastomers. Broad
applicability and simple technology of production are the
attractive features of this class of TPES. NBR/PVC thermoplastic
elastomers were selected for this investigation due
to the versatility of PVC, its number one position, low
cost. ability to Ina compounded into various flexible and
rigid form with good physical and chemical and weathering
properties etc., which will be passed over to PVC blends
especially NBR/PVC blends which are known to form miscible
systems
Description:
Department of Polymer Science and Rubber
Technology, Cochin University of Science and Technology
Lizen, Mathews; Dr.Chandramohanakumar, N(Department of Chemical Oceanography, School of Marine Sciences, 2000)
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Abstract:
In the present study the nutrient dynamics and fertility of Kuttanad waters is addressed. Kuttanad represent a wetland system with considerable agricultural activities. The hydrographical features of the Kuttanad waters are controlled by discharges from Manimala, Meenachil, Pamba, Achencoil and Muvattupuzha rivers and also by tidal intrusions of saline waters from Cochin backwaters during summers. The fertility of these water bodies were significantly high and supported good agricultural production. Kuttanad water forms the southern part of this aquatic systems and is considered as the most productive zones. As a part of the management scheme for a higher agricultural activity, the Thannermukkam bund was constructed to block and regulate the intrusion of saline water. The increased use of artificial fertilizers along with stagnant character of the water body in this area has resulted in sharp decline in the water quality, productivity and aquatic resources.
Lizen, Mathews; Dr.Chandramohanakumar, N(Cochin University of Science and Technology, January , 2000)
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Abstract:
In the present study the nutrient dynamics and fertility of Kuttanad waters is addressed. Kuttanad represent a wetland system with considerable agricultural activities. The hydrographical features of the Kuttanad waters are controlled by discharges from Manimala, Meenachil, Pamba, Achencoil and Muvattupuzha rivers and also by tidal intrusions of saline waters from Cochin backwaters during summers. The fertility of these water bodies were significantly high and supported good agricultural production. Kuttanad water forms the southern part of this aquatic systems and is considered as the most productive zones. As a part of the management scheme for a higher agricultural activity, the Thannermukkam bund was constructed to block and regulate the intrusion of saline water. The increased use of artificial fertilizers along with stagnant character of the water body in this area has resulted in sharp decline in the water quality, productivity and aquatic resources.
Prasanth A, Pillai; Dr.Mohan Kumar, K(Cochin University of Science & Technology, October , 2008)
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Abstract:
The present study illustrates the biennial oscillation in different ocean-atmosphere
parameters associated with interannual variability of Indian summer monsoon rainfall.It also accounts the role of different processes like ENSO, IOD, QBO and ISO in the monsoon variability during the TBO years.
Description:
Department of Atmospheric Sciences,
Cochin University of Science and Technology
Muthu Velan, B; Dr. Krishnamurthy, Chennubhotla, V S(Cochin University of Science and Technology, June , 1994)
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Abstract:
The importance of marine algae, often referred to
as seaweeds, has been felt over a long time and is
appreciated more and more in modern times. The economic
value of marine algae is understood both indirectly and
directly. The indirect benefit is due to the role of marine
phytoplankton as well as the benthic macrophyte biomass
along the shore and in the continental shelf, in primary
production of the sea. Direct benefit includes the use of
marine algae as food, feed, fertilizer and as source of
various products of commercial importance such as agar and
alginic acid. Hence to understand the potential resources of
seaweeds, their distribution, density, standing crop and
interrelated environmental parameters, a detailed study
(survey and ecological work) was carried out for a period of
20 months from August 1988 to March 1990 in South Andaman,
North Andaman, Middle Andaman, Havelock, Neil, Car Nicobar,
Terassa, Chowra and Bumpoka islands. However in South
Andaman, data were collected from five fixed stations
fortnightly during this period for the purpose of modelling
and system analysis.
Rekha R mallia; Dr.Prathapan, S(Cochin University of Science and Technology, December , 2007)
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Abstract:
The thesis entitled ‘Studies on the Solvent Dependence in the
Reaction of a Few (Anthracen-9-yl)methylamines and Sulfanes with
Reactive Acetylenes’ is divided into six chapters. ln Chapter l a general
survey of electron transfer reactions, Diels-Alder reactions and Michael-type
additions is presented. A detailed discussion on the synthesis of several
(anthracen-9-yl)methylamines is presented in Chapter 2. In Chapter 3,
results of preliminary photophysical studies on a few (anthracen-9yl)
methylamines are compiled. A detailed discussion on extensive
examination of dependence in the reaction of (anthracen-9-yl)methylamines
with reactive acetylenes is presented Chapter 4. Details on the synthesis and
reaction of a few (anthracen-9-yl)methylsulfanes with DMAD are described in
Chapter 5.