[en] Most of the HI elastic scattering studies suffer from the inevitable ambiguity of a potential extracted from a limited set of forward angle data at low energies and also confined to small region of the potential tail. The 16O+28Si system overcomes this ambiguity as a variety of experimental data are available at vast energies over full angular range. Here, real part of the nuclear potential is microscopically calculated for both oblate and prolate shapes of silicon nucleus and an average is taken. The imaginary part of the nuclear potential is assumed by adjusting a dimensionless strength parameter in the above real part. This approach reproduces fairly well the experimental DCS over full angular range, excitation function at cm = 90 degrees and 180 degrees and also backangle anomaly (ALAS)

No abstract available

[en] The multilayer adsorption of liquid ⁴He on graphite was studied by using third sound, a substrate-induced surface wave in a superfluid film, to probe the ⁴He film-vapor interface. The third-sound velocity decreases with increasing film thickness and can be used to monitor the film growth. Graphite, forms of which have large areas of atomic uniformity, is an ideal substrate for the study of film growth and layering. An annular resonator made out of graphite fibers was used for the experiments. Such a resonator avoids problems such as capillary condensation present in earlier resonance experiments with graphite foam and vapor sound interference present in time-of-flight experiments with highly oriented pyrolitic graphite (HOPG). Measurements of film growth were made between temperatures of 0.35 and 1.25 K. The third-sound resonance frequency, which is proportional to the third-sound velocity, was used to follow the film growth. Simultaneous measurements of the third-sound velocity on glass provide an independent measure of the film thickness. Results obtained show continuous film growth up to at least 25 to 30 layers on graphite. Oscillations of the third-sound velocity for low film coverages shown evidence of layering of the film

[en] The data from the world wide grid of neutron monitoring stations was analyzed for a comparative study of the phase of diurnal anisotropy on quiet and disturbed days on a long term basis up to the recent period. It has been observed that the phase of the diurnal anisotropy on disturbed days, where the value of the Ap-index is higher, is found to shift towards earlier hours in comparison to the phase of the diurnal anisotropy on quiet days, where the value of Ap-index is lower at all the stations from 1965 to 71. Such a trend is not observable for the later period. This affect is found to be more pronounced on equatorial stations, in particular, in comparison to high latitude stations. It was derived from these observational facts that the relationship between Ap-index and the phase of the diurnal anisotropy is not invariant throughout the period of consideration. Furthermore, the exact cause of such a drastic change is not known, but it demonstrates very clearly that the interplanetary conditions, which are responsible for both diurnal anisotropy of cosmic ray intensity, and the geomagnetic Ap-index variation have drastically changed during the period 1971 and onwards

[en] The spectral exponents of the diurnal and semidiurnal anisotropies are studied on quiet and disturbed days for a period from 1964 to 75. It has been observed for the diurnal anisotropy that the spectral exponent for quiet days is 0.0 from 1964 to 70, however during 1971 and onwards its value is found different from zero and is -0.4; for disturbed days the spectral exponent is observed to be 0.0 from 1964 to 75 with an exception of the year 1966. Further, it has been observed for the semi-diurnal anisotropy that the best value for the spectral exponent on quiet days being + 0.6 from 1964 to 74; however on disturbed days the value of spectral exponent is sometimes negative or positive but different from zero. It was derived from the present investigation that superimposed on the corotational anisotropy, expected from a balance between outward radial convection and inward field aligned diffusion, there is an additional component operating during the period under consideration

[en] During the past 20 years considerable progress has been made in establishing the presence of metallic ions in the sporadic E layers at mid latitudes and as discrete patches at high altitudes in the equatorial ionosphere. The E-region observations have been based on rocket flights, which represent local conditions faithfully. But the global distribution of metallic ions and variations relating to changes in season, local time, magnetic activity, etc., which require satellite data, have been largely unexamined. This work presents a few aspects of this missing global distribution over an altitude range of 100 to 1000 km, using the data from AE-C, AE-D, and OGO-6 satellites and the rocket flights 18.117 and 18.118 from Wallops Island on July 12 and 13, 1971. The rocket data provide a day-night pair of vertical profiles that include altitudes not covered by the satellites. Results are presented for Mg⁺, Al⁺, Si⁺ and Fe⁺ ions in terms of their detection probabilities, median concentrations and relative abundances with respect to Mg⁺ ions as a function of significant geophysical parameters. Na⁺ and K⁺ ions have been excluded from this study because alkali metal ions driven off the spacecraft hamper the measurement of ambient Na⁺ and K⁺ ions. This study has indicated that in general different metallic ions appear together in comparable concentrations except for Al⁺, which is an order of magnitude smaller than the others

No abstract available

[en] Using the isospin-dependent quantum molecular dynamical model, we systematically study the role of symmetry energy with and without momentum-dependent interactions on the global nuclear stopping. We simulate the reactions by varying the total mass of the system from 80 to 394 at different beam energies from 30 to 1000 MeV/nucleon over central and semi-central geometries. The nuclear stopping is found to be sensitive towards the momentum-dependent interactions and symmetry energy at low incident energies. The momentum-dependent interactions are found to weaken the finite size effects in nuclear stopping. (authors)

[en] Nuclear Energy and management of safety therein, has a somewhat distinct streak in that from its early days it has had the privilege of being shaped and supervised by the eminent scientists and engineers, in fact it owes its very origin to them. This unique engagement has resulted in culmination of the several safety elements like defence-in-depth in the form of multiple safety layers, redundancy, diversity and physical separation of components, protection against single failures as well as common cause failures right at the beginning of designing a nuclear reactor. The fundamental principles followed by regulators across the globe have many similarities such as, creation of an organization which has a conflict-free primary responsibility of safety supervision, laying down the safety criteria and requirements for the respective industry and developing and using various tools and regulatory methodology to ensure adherence to the laid down regulatory requirements. Yet the regulatory regimes in different States have evolved differently and therefore, has certain attributes which are unique to these and confer on them their identity.

No abstract available