23 research outputs found
Exploratory trawl fishing and ground fish resources along the Kerala coast and adjacent waters
The paper deals with exploratory fishing operations mainly trawling, conducted along Kerj^a Coast and
adjacent waters since 1908. Early operations prior to 1950 demonstrated tlie occurrence of rich grounds
for percoid fishes in the Cape Comorin area and good hand-line fkhiiig grounds off South Kerala Coast.
Bull trawling in the Cannanore-Cape Comorin region by the vessels of the Deep Sea Fishing, Station
of the Government of India showed that elasmobranchs and miscellaneous fish comprising small sciaenids,
lizard fishes, flatheads, etc., were common for the area with a dominant catfish element in the Cannanoi«-
Calicut sector, perch element south of AUeppey including Cape Comorin grounds and a transitional middle
sector having a few catfishes and perches.
Inshore otter trawl operations with medium-sized boats were increasingly carried out by the lndo>.Norwegian
Project, Deep Sea Fishing Station and private agencies mainly centred around Coehin during; the last
decade. Deep Sea Fishing Station operations in the region revealed a composition of about SO % miscellaaeous
fish, 20-35% prawns, 8-14% Nemipterus japonicus, 6-14% elasmobranchs and 1-3% Laeiarius faciariiu.
These operations showed the area between Calicut and Alleppey to be more productive, those off river
and bar mouths yielding good quantity of prawns. The catch rate of prawns and fish increased steadily
around Cochin from 1957 to 1961 and since then showed a slight decline. The picture is indicative of excessive
fishing pressure over a limited area. This points to the necessity for even dispersal of fishing effort.
Indo-Norwegian Project hand-line fishing operations provided considerable information regarding the
'Kalava' (Epinephelus spp.) resources of the rocky grounds on the continental shelf usually lying in 70-110 m
depth zone off Kerala Coast.
The occurrence of a variety of deep sea prawns, densely shoaling bathypelagic fishes like Cubiceps uatalensis,
Chlorophthatmus spp., Antigonia spp., mid-water concentrations of balistids etc. have been found out
along the Kerala Coast mainly by the fishing operations of the Indo-Norwegian Project. These as well as
the "Kalava" resources could be better exploited with increased effort
The fishery, biology and stock assessment of jew fish resources of India
Sciaenids are one of the major component of the demersal
trawl The total catch of this resource during 1990-94 period was
1.50,142 t contributing 8.86% to the demersal catch of India. A
number of species are found in different states of India. Of which
biological and stock assessment studies were made on eleven important
species. Crustaceans and fish appear to be the chief food
in Juvenile and adult stage respectively. Most of the species have a
protracted spawning season. Among all the species studied the largest
asymptotic length was estimated for O.ruber from Tuticorin and
the smallest for J. sina from Cochin. The highest Z of 7.59 was
recorded for K. axillaris from Chennai and the lowest was for O.
cuvierifrom Mumbai. The average exploitation rate (E) and the Lc/
Lao was 0.62 and 0.53 respectively. The present yield is 91.222 t
and the MSY is 1.42,613 t for all the species taken together. The
exploitation rate for almost all the stocks in the states appears to be
more than the optimum leve
Performance characteristics of positive and negative delayed feedback on chaotic dynamics of directly modulated InGaAsP semiconductor lasers
The chaotic dynamics of directly modulated semiconductor lasers with delayed
optoelectronic feedback is studied numerically. The effects of positive and
negative delayed optoelectronic feedback in producing chaotic outputs from such
lasers with nonlinear gain reduction in its optimum value range is investigated
using bifurcation diagrams. The results are confirmed by calculating the
Lyapunov exponents. A negative delayed optoelectronic feedback configuration is
found to be more effective in inducing chaotic dynamics to such systems with
nonlinear gain reduction factor in the practical value range.Comment: 18 pages, 16 figures. To appear In Pramana - journal of physic
Total anomalous pulmonary venous drainage
This article does not have an abstract
Surgical correction of anomalous pulmonary venous drainage. Mixed type-case report
This article does not have an abstract
Spectral Characterization of Laser Induced Plasma from Titanium Dioxide
Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically
analysed. The main chemical species are identified and the spatio-temporal distribution of
the plasma parameters such as electron temperature and density are characterized based on the
study of spectral distribution of the line intensities and their broadening characteristics. The parameters
of laser induced plasma vary quickly owing to its expansion at low background pressure
and the possible deviations from local thermodynamic equilibrium conditions are tested to show
its validity
Spectral Characterization of Laser Induced Plasma from Titanium Dioxide
Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically
analysed. The main chemical species are identified and the spatio-temporal distribution of
the plasma parameters such as electron temperature and density are characterized based on the
study of spectral distribution of the line intensities and their broadening characteristics. The parameters
of laser induced plasma vary quickly owing to its expansion at low background pressure
and the possible deviations from local thermodynamic equilibrium conditions are tested to show
its validity