Quantum Mechanics of a Rotating Billiard

Integrability of a square billiard is spontaneously broken as it rotates about one of its corners. The system becomes quasi-integrable where the invariant tori are broken with respect to a certain parameter, $\lambda = 2E/\omega^{2}$ where E is the energy of the particle inside the billiard and $\omega$ is the angular frequency of rotation of billiard. We study the system classically and quantum mechanically in view of obtaining a correspondence in the two descriptions. Classical phase space in Poincar\'{e} surface of section shows transition from regular to chaotic motion as the parameter $\lambda$ is decreased. In the Quantum counterpart, the spectral statistics shows a transition from Poisson to Wigner distribution as the system turns chaotic with decrease in $\lambda$. The wavefunction statistics however show breakdown of time-reversal symmetry as $\lambda$ decreases

Recovery of Zinc from Zinc Ash

The ever increasing need of zinc as a coating material on steels has compelled the galvanizers to have a rclook on the economic and effective use of this material. The annual world wide consumption of zinc for hot Clip galv-anizing is around 600000t. The effective utilisation of zinc in different galvanizing plant throughout the world averages 78% but in our plant it comes to 58% only. The world average of zinc loss as zinc ash is 3% in hot dip galvanizing while at Tata Steel zinc loss is about 14 - 16% (shown in Fig. 1). Of late, increased attention is being paid the world over for the recovery of scarce material from industrial waste. Particularly in India, it has drawn a great deal of importance as the country at present is not self sufficient in the production of zinc and has to import a substantial amount every yea

Economics of Rice Production in Pyuthan District of Nepal

A research was conducted at Pyuthan district in order to access the profitability of rice production in Pyuthan during the summer season of 2018-2019. Altogether of 70 respondents were selected randomly and surveyed with semi-structured interview schedule. The results revealed that the average land holding was 0.45 hectare, and the average rice cultivation area was 0.34 hectare. On the basis of average rice cultivation area, farmers were categorized as small (39) and large (31). The cost and return was calculated among both the category. t- test was used to compare the mean costs of inputs between small and large farmers. Cost for agronomic operations was found far higher (more than 70%) in both the category in compared to the cost of inputs. Contribution of rice grains and straw to overall return was 72.65% and 27.35% respectively. Benefit Cost ratio was found greater among large farmers. The average B:C ratio was 1.51, which was fairly higher than 1.14 in Dang district indicating the investment of rice production is expected to deliver a positive net return to the farmers of the study area. In a nutshell, rice cultivation is an important enterprise that should be encouraged, considering the fact that it is a major staple crop