5,487 research outputs found
Socio-economic dimension of fish farming in Assam
Information on socio-economic framework of the fish farmer
community forms a benchmark for policy formulation to develop this
economically backward sector. Very few studies have been conducted on the
socio-economic aspect of fish farming. Two districts of Assam, Darrang and
Nagaon, were selected for this study where 120 respondents from each district
were selected randomly. The characteristics representing the personnel and
socio-economic attributes of the fish farmers are presented in this paper. The
socio-economic status of fish farmers has to be improved by bringing the
modern concepts of fish farming to the doorstep of farmers
What can the SNO Neutral Current Rate teach us about the Solar Neutrino Anomaly
We investigate how the anticipated neutral current rate from will
sharpen our understanding of the solar neutrino anomaly. Quantitative analyses
are performed with representative values of this rate in the expected range of
. This would provide a signal for transition
into a state containing an active neutrino component. Assuming this state to be
purely active one can estimate both the neutrino flux and the
survival probability to a much higher precision than currently possible.
Finally the measured value of the rate will have profound implications for
the mass and mixing parameters of the solar neutrino oscillation solution.Comment: Brief discussion on the first NC result from SNO added; final version
to be published in the MPL
Gravitational collapse from smooth initial data with vanishing radial pressure
We study here the spherical gravitational collapse assuming initial data to
be necessarily smooth, as motivated by the requirements based on physical
reasonableness. A tangential pressure model is constructed and analyzed in
order to understand the final fate of collapse explicitly in terms of the
density and pressure parameters at the initial epoch from which the
collapsedevelops. It is seen that both black holes and naked singularities are
produced as collapse end states even when the initial data is smooth. We show
that the outcome is decided entirely in terms of the initial data, as given by
density, pressure and velocity profiles at the initial epoch, from which the
collapse evolves.Comment: 10 pages,3 figures,revtex4,Revised Versio
Earth Matter Effects at Very Long Baselines and the Neutrino Mass Hierarchy
We study matter effects which arise in the muon neutrino oscillation and
survival probabilities relevant to atmospheric neutrino and very long baseline
beam experiments. The inter-relations between the three probabilities P_{\mu
e}, P_{\mu \tau} and P_{\mu \mu} are examined. It is shown that large and
observable sensitivity to the neutrino mass hierarchy can be present in P_{\mu
\mu} and P_{\mu \tau}. We emphasize that at baselines of > 7000 Km, matter
effects in P_{\mu \tau} can be large under certain conditions. The muon
survival rates in experiments with very long baselines thus depend on matter
effects in both P_{\mu \tau} and P_{\mu e}. We indicate where these effects are
sensitive to \theta_{13}, and identify ranges of E and L where the event rates
increase with decreasing \theta_{13}, providing a handle to probe small
\theta_{13}. The effect of parameter degeneracies in the three probabilities at
these baselines and energies is studied in detail. Realistic event rate
calculations are performed for a charge discriminating 100 kT iron calorimeter
which demonstrate the possibility of realising the goal of determining the
neutrino mass hierarchy using atmospheric neutrinos. It is shown that a careful
selection of energy and baseline ranges is necessary in order to obtain a
statistically significant signal, and that the effects are largest in bins
where matter effects in both P_{\mu e} and P_{\mu \tau} combine constructively.
Under these conditions, upto a 4\sigma signal for matter effects is possible
(for \Delta_{31}>0) within a timescale appreciably shorter than the one
anticipated for neutrino factories.Comment: 40 pages, 27 figures, version to match the published versio
Time domain study of frequency-power correlation in spin-torque oscillators
This paper describes a numerical experiment, based on full micromagnetic
simulations of current-driven magnetization dynamics in nanoscale spin valves,
to identify the origins of spectral linewidth broadening in spin torque
oscillators. Our numerical results show two qualitatively different regimes of
magnetization dynamics at zero temperature: regular (single-mode precessional
dynamics) and chaotic. In the regular regime, the dependence of the oscillator
integrated power on frequency is linear, and consequently the dynamics is well
described by the analytical theory of current-driven magnetization dynamics for
moderate amplitudes of oscillations. We observe that for higher oscillator
amplitudes, the functional dependence of the oscillator integrated power as a
function of frequency is not a single-valued function and can be described
numerically via introduction of nonlinear oscillator power. For a range of
currents in the regular regime, the oscillator spectral linewidth is a linear
function of temperature. In the chaotic regime found at large current values,
the linewidth is not described by the analytical theory. In this regime we
observe the oscillator linewidth broadening, which originates from sudden jumps
of frequency of the oscillator arising from random domain wall nucleation and
propagation through the sample. This intermittent behavior is revealed through
a wavelet analysis that gives superior description of the frequency jumps
compared to several other techniques.Comment: 11 pages, 4 figures to appear in PR
Modeling for the Modified Atmosphere Packaging of Sapota Fruit
Modified atmospheric packaging utilizes polymeric films with selective permeability for O2 & CO2 and modifies the storage environment by lowering O2 concentration and increasing CO2 concentration. Modeling and design of the Sapota fruit for modified atmosphere storage was done with different packaging materials for the higher shelf life. Based on the respiration rate and permeability of the packaging material the suitable packaging films obtained for the modified atmospheric packaging of Sapota fruit were low density Polyethylene, Polyvinyl chloride, Polypropylene and Polystyrene film. Saran and Polyester films were found to be unsuitable for MAP storage of the Sapota fruit. The developed model provides an effective way for selection of the proper packaging material for Sapota fruit and this model can also be employed for designing packaging films for other fruits and vegetables
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