760 research outputs found
By-catch of the shrimp fishery in India
Every year as much as 21 million tonnes of edible marine fish are thrown away at sea by shrimp trawlers, which amounts to roughly the same quantity of fish eaten annually by the people of the developing countries in a world of increasing hunger we cannot afford to indulge in the luxury of this practice of dumping the trash fish over-board the fishing vessel in this connection a study was made to understand the shrimping by-catch and its utilisation in this country and the results are reported here. The present study makes it clear that nothing much from the shrimp trawler catches is wasted in india and almost all the fishes, which are termed trash fish and discarded over board the vessel in some of the developed countries, are utilised either for human consumption or as fish meal and fish manure. However it is to be pointed out that the handling, processing and utilization of the fish catches, need further improvement
Multiple plasmon resonances in naturally-occurring multiwall nanotubes: infrared spectra of chrysotile asbestos
Chrysotile asbestos is formed by densely packed bundles of multiwall hollow
nanotubes. Each wall in the nanotubes is a cylindrically wrapped layer of . We show by experiment and theory that the infrared spectrum
of chrysotile presents multiple plasmon resonances in the Si-O stretching
bands. These collective charge excitations are universal features of the
nanotubes that are obtained by cylindrically wrapping an anisotropic material.
The multiple plasmons can be observed if the width of the resonances is
sufficiently small as in chrysotile.Comment: 4 pages, 5 figures. Revtex4 compuscript. Misprint in Eq.(6) correcte
Serializing the Parallelism in Parallel Communicating Pushdown Automata Systems
We consider parallel communicating pushdown automata systems (PCPA) and
define a property called known communication for it. We use this property to
prove that the power of a variant of PCPA, called returning centralized
parallel communicating pushdown automata (RCPCPA), is equivalent to that of
multi-head pushdown automata. The above result presents a new sub-class of
returning parallel communicating pushdown automata systems (RPCPA) called
simple-RPCPA and we show that it can be written as a finite intersection of
multi-head pushdown automata systems
Present status of exploitation of fish and shellfish resources: Marine fish production of maritime states Of the west coast of India
To highlight the fishery in monsoon, an attempt has been made In this paper to evaluate the impad of monsoon
fishing on the exploited marine fish stocks in the west coast of India and the trends In the production of various group
in different seasons discussed.
Except in Kerala where monsoon fishing is intensive due to the Mud Bank fishery and trawling off Sakthlkulangara
and Kochi, in the rest of the coast fishing adivitics are not as intensive as in Kerala during monsoon. The major
gears used during monsoon are trawls and ring seines in Keral
Weak Gravitational Field in Finsler-Randers Space and Raychaudhuri Equation
The linearized form of the metric of a Finsler - Randers space is studied in
relation to the equations of motion, the deviation of geodesics and the
generalized Raychaudhuri equation are given for a weak gravitational field.
This equation is also derived in the framework of a tangent bundle. By using
Cartan or Berwald-like connections we get some types "gravito -
electromagnetic" curvature. In addition we investigate the conditions under
which a definite Lagrangian in a Randers space leads to Einstein field
equations under the presence of electromagnetic field. Finally, some
applications of the weak field in a generalized Finsler spacetime for
gravitational waves are given.Comment: 22 pages, matches version published in GER
Packages of Practices for Sustainable, Ecofriendly Mariculture (Land-based Saline Aquaculture and Seafarming)
The problems of fast growing human population and protein deficit, particularly in the developing countries continue to exert pressure on the fisheries resources available for exploitation in the wild water bodies. The increasingly limited opportunities in the capture fisheries sector have generated considerable interest in aquaculture
Study of the transient nature of classical Be stars using multi-epoch optical spectroscopy
Variability is a commonly observed property of classical Be stars (CBe)
stars. In extreme cases, complete disappearance of the H{\alpha} emission line
occurs, indicating a disc-less state in CBe stars. The disc-loss and
reappearing phases can be identified by studying the H{\alpha} line profiles of
CBe stars on a regular basis. In this paper, we present the study of a set of
selected 9 bright CBe stars, in the wavelength range of 6200 - 6700 {\AA}, to
better understand their disc transient nature through continuous monitoring of
their H{\alpha} line profile variations for 5 consecutive years (2015 -- 2019).
Based on our observations, we suggest that 4 of the program stars (HD 4180, HD
142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes,
whereas one other star (HD 23302) might be passing through disc formation
phase. The remaining 4 stars (HD 237056, HD 33357, HD 38708 and HD 60855) have
shown signs of hosting a stable disc in recent epochs. Through visual
inspection of the overall variation observed in the H{\alpha} EW for these
stars, we classified them into groups of growing, stable and dissipating discs,
respectively. Moreover, our comparative analysis using the BeSS database points
out that the star HD 60855 has passed through a disc-less episode in 2008, with
its disc formation happening probably over a timescale of only 2 months,
between January and March 2008.Comment: 19 pages, 7 figures, 2 tables, accepted in JAp
A Guide to Localized Frames and Applications to Galerkin-like Representations of Operators
This chapter offers a detailed survey on intrinsically localized frames and
the corresponding matrix representation of operators. We re-investigate the
properties of localized frames and the associated Banach spaces in full detail.
We investigate the representation of operators using localized frames in a
Galerkin-type scheme. We show how the boundedness and the invertibility of
matrices and operators are linked and give some sufficient and necessary
conditions for the boundedness of operators between the associated Banach
spaces.Comment: 32 page
Tuna fisheries in India: Recent trends
Tuna is one of the least exploited resources of the Indian seas accounting for 0.98 % of the total marine
fish catch of India at the 1978 level. On the other hand tuna resources have been exploited by countries such as Japan, Korea and Taiwan from the Indian Ocean. Relevant portions of the recommendations of the 'Symposium on scombroid fishes' held at Mandapam camp. The authorities involved with the planning of the Indian Ocean Expedition give due consideration to gathering and collating the information which should be useful in aiding the development of high seas fisheries for scombroid fishes in the Indian Ocean. In the context of these developments and the need for efficient utilisation of the resources of the Exclusive Economic Zone, a brief account on the trend in the tuna fisheries in the country is presented here
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