Prospects for Oyster Culture in Kerala Backwaters

The oysters are highly esteemed sea foods in Japan, U.S.A. and Europe. It is stated that as early as the first century B.C., the Romans practised simple method of oyster culture by collecting oyster seed and growing them for food. In the world aquaculture production of 1,53,22,703 t in 1990, the molluscs accounted for 29,65.265 t forming 19.35%

Muon and neutrino results from KGF experiment at a depth of 7000 hg/square cm

The KGF nucleon decay experiment at a depth of 7000 hg/sq cm has provided valuable data on muons and neutrinos. The detector comprised of 34 crossed layers of proportional counters (cross section 10 x 10 sq cm; lengths 4m and 6m) sandwiched between 1.2 cm thick iron plates can record tracks of charged particles to an accuracy of 1 deg from tracks that traverse the whole of the detector. A special two-fold coincidence system enables the detector to record charged particles that enter at very large zenith angles. In a live time of 3.6 years about 2600 events have been recorded. These events include atmospheric muons, neutrino induced muons from rock, stopping muons, showers and events which have their production vertex inside the detectors. The results on atmospheric muons and neutrino events are presented

Prospects for development of oyster culture in India

Oysters occur all along the Indian coasts in backwaters, bays and estuaries forming subsistence fisheries. The meat is consumed locally and of late there is growing demand for it in some parts of the country. The shell is used in lime based industries. At present oyster culture is not practised in the country except for the experimental culture conducted by the CMFRI

Results on nucleon life-time from the Kolar gold field experiment

The KGF nucleon decay experiment has been in operation since October 1980 with a 140 ton calorimetric detector at a depth of 2.3 Km underground. The detector comprises 34 layers of proportional counters arranged in an orthogonal geometry with 12 mm thick iron plates in between successive layers. The proportional counters are made up of square (10 x 10 square centimeters) iron plates of wall thickness 2.3 mm. Each of the 1600 counters is instrumented to provide data on ionization, DE/dx and arrival time. The visible energy of a particle is determined to an accuracy of approximately 20% from the ionization and range of its track. The end point ionization of a stopping track provides the direction of motion as well as the nature of the particle (mu/pi,k,p). Decay of mu is recorded with an overall efficiency of only 20% in view of the thickness of 13 g/square centimeters between successive layers

Saltwater pearl fisheries and pearl culture in India: An update

Recently. C. Ricbard Fassler (1991 a, 1991 b, 1992) gave an overview of pearl culture in the world and discussed both "opportunities and obstacles" for the development of pearl culture. While Japan still bolds the monopoly, China is fast catching up and several countries are producing pearls on commercial lines, mostly with Japanese collaboration, the notable being Australia, Frencb Polynesia, Indonesia, New Caledonia and Cook Islands, Fassler (1991 a) stated that thougb the Indians bave developed their own pearl industry, there is little publisbed information

Experimental culture of the Indian oyster, Crassostrea madrasensis (Preston) at Ashtamudi lake, Kerala

The edible oyster, Crassostrea Madrasensis, (P reston) occurs attached to hard substrates in the intertidal and subtidal regions of the coastal areas. Oyster meat is a highly esteemed seafood and aquaculture of oysters is widely prevalent and well established in many temperate countri

Effect of natural convection on oscillating flow in a pipe with cryogenic temperature difference across the ends

The effect of natural convection on the oscillatory flow in an open-ended pipe driven by a timewise sinusoidally varying pressure at one end and subjected to an ambient-to-cryogenic temperature difference across the ends, is numerically studied. Conjugate effects arising out of the interaction of oscillatory flow with heat conduction in the pipe wall are taken into account by considering a finite thickness wall with an insulated exterior surface. Two cases, namely, one with natural convection acting downwards and the other, with natural convection acting upwards, are considered. The full set of compressible flow equations with axissymmetry are solved using a pressure correction algorithm. Parametric studies are conducted with frequencies in the range 5–15 Hz for an end-to-end temperature difference of 200 and 50 K. Results are obtained for the variation of velocity, temperature, Nusselt number and the phase relationship between mass flow rate and temperature. It is found that the Rayleigh number has a minimal effect on the time averaged Nusselt number and phase angle. However, it does influence the local variation of velocity and Nusselt number over one cycle. The natural convection and pressure amplitude have influence on the energy flow through the gas and solid

Data acquisition system for phase-2 KGF proton decay experiment

Phase-2 of KGF proton decay experiment using 4000 proportional counters will start operating from middle of 1985. The detection systems, in addition to measuring the time information to an accuracy of 200 n see, also records ionization in the hit counters. It also monitors different characteristics of the counters like pulse height spectrum, pulse width spectrum and counting rate. The acquisition system is discussed